Mining explosion-proof storage battery parallel operation standby power system and power supply

Abstract

The invention provides a mining explosion-proof storage battery parallel operation standby power system which comprises a charging control module, a discharging control module, a reverse current blocking module, a mains supply voltage loss circuit and a battery management system. And the charging branch and the discharging branch are used for controlling the main power storage battery pack to charge and discharge, and controlling the power supply switching between the main power and the standby power and the power supply switching between the commercial power and the battery. According to the scheme, the actual market requirement is met, the advantages of being simple in structure, low in cost and convenient to produce, install and debug are achieved, and good technical effects and economic benefits are achieved.

Description

Technical Field

[0001] The present invention relates to the field of mining power supplies, and in particular to a mining flameproof battery parallel backup power system and a power supply. Background Art

[0002] With the development of intelligent mining in my country, the power supply quality requirements of underground coal mines are becoming more and more stringent. Batteries with flameproof and intrinsically safe characteristics have become standard equipment for power supply places such as substations and communication stations. In the event of a power outage, they can continue to connect to the mains to provide working power for the subsequent power loads.

[0003] As the number of electrical equipment in underground power-using places increases, a single battery power supply often cannot meet the power supply requirements, and multiple batteries are needed. Since the capacity of each battery power supply is different, the type of load assigned is also different, and the power size of the load is also changing when the load is running. Therefore, the backup time of each power supply will be different when the mains voltage is lost. In the case where the same backup time needs to be provided to multiple loads, multiple power supplies need to be used in parallel to achieve the purpose of the same backup time. In some cases, it is necessary to ensure the power supply time of important equipment, and some minor equipment may be shut down, and the power supply with lighter load is used as the power supply for important equipment, and multiple power supplies are used in parallel.

[0004] On the other hand, the parallel use of batteries needs to meet relevant safety standards. For example, according to the current "Supplementary Safety Technical Requirements for Lithium-ion Batteries for Mining" (hereinafter referred to as "Supplementary Requirements"), lithium-ion batteries are not allowed to be connected in parallel in any form in the flameproof cavity. In addition, in order to extend the service life of the battery, the parallel use of batteries must also meet the requirements of unidirectional charging, separate charging and discharging ports, and fast switching.

[0005] Therefore, in view of the above practical parallel backup power usage needs and corresponding safety standards, it is of great significance to design a battery parallel backup power solution suitable for underground use. Summary of the invention

[0006] The invention provides a mining flameproof battery parallel power backup system and a power supply, which are used to solve the problem of parallel power backup under the premise of complying with safety standards.

[0007] To solve the above technical problems, the present invention is achieved as follows:

[0008] On the one hand, the present invention provides a mining flameproof battery parallel backup system, comprising: a charging control module (1), a discharging control module (2), a reverse current blocking module (3), a mains voltage loss circuit (4) and a battery management system (5), wherein:

[0009] The voltage loss signal input end of the battery management system (5) is connected to the output end of the mains voltage loss circuit (4) to detect the mains power state;

[0010] The voltage collection line of the battery management system (5) is connected to each battery in the main battery pack (7) to detect the battery status;

[0011] The charging control terminal of the battery management system (5) is connected to the charging control module (1) and the reverse current blocking module (3) to form a charging branch circuit, so that the main power storage battery group (7) does not supply power to the outside in a charging state;

[0012] The discharge control terminal of the battery management system (5) is connected to the discharge control module (2) and the reverse current blocking module (3) to form a discharge branch circuit, so that the main power storage battery group (7) is not connected in parallel with the battery of the backup power supply in the discharge state;

[0013] The battery management system (5) controls the charging and discharging of the main power storage battery pack (7) and controls the power supply switching between the main power and the backup power, and between the main power and the battery, based on the detected main power status and the battery status, using the charging branch and the discharging branch.

[0014] On the other hand, the present invention also provides a mine flameproof battery power supply, which is suitable for parallel use with a backup power supply, and the power supply comprises:

[0015] As the backup power system mentioned above, the backup power system is provided with a battery chamber; and,

[0016] A storage battery pack is arranged in the battery cavity.

[0017] The technical solution of the present invention adopts a DC relay, a DC contactor, a high-power diode, a battery management system, a mains voltage loss circuit and a reverse drive circuit, which not only solves the problem of parallel use of the main and backup power supplies when the mains voltage is lost, but also achieves the following technical effects: (1) When the mains voltage is normal, the batteries of the main and backup power supplies are disconnected and no mutual energy flow occurs; (2) The battery charging and discharging ports are separated; (3) When the mains voltage is lost, the main power supply is first discharged by the battery in the battery cavity of the power supply, and after the discharge is completed, it is switched to the battery of the backup power supply for power supply. At the same time, the battery of the main power supply quits power supply and is not connected to the backup power battery, meeting the provisions of the "Supplementary Requirements"; (4) The power supply switching is short and fast (within 10ms), avoiding voltage drop during the switching process and interfering with the load; (5) When the mains voltage is restored, the main power supply is quickly switched to the main power charging state, and the load is directly powered by the mains. The solution of the present invention not only meets the actual market demand, but also has the advantages of simple structure, low cost, easy production and installation and debugging, and has good technical effects and economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present disclosure or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 A schematic diagram of the structure of a backup power system provided in an embodiment of the present disclosure;

[0020] Figure 2 A circuit schematic diagram of a backup power system provided in an embodiment of the present disclosure;

[0021] Figure 3 A circuit schematic diagram of a reverse current blocking module implemented in an embodiment of the present disclosure;

[0022] Figure 4 A circuit schematic diagram of a mains voltage loss circuit implemented in an embodiment of the present disclosure;

[0023] Figure 5 The schematic diagram of the circuit for implementing the voltage reduction scheme of the battery voltage conversion module in the embodiment of the present disclosure is shown. DETAILED DESCRIPTION

[0024] In order to enable those skilled in the art to better understand the technical solutions in the present disclosure, the technical solutions of the present disclosure will be clearly and completely described below in conjunction with the drawings in the embodiments of the present disclosure. Obviously, the described embodiments are only part of the embodiments of the present disclosure, rather than all of the embodiments. Based on the embodiments of the present disclosure, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present disclosure. In addition, for the sake of clarity, parts that are not related to the description of the exemplary embodiments are omitted in the drawings.

[0025] In this specification, it should be understood that terms such as "including" or "having" are intended to indicate the existence of the features, numbers, steps, behaviors, components, parts or combinations thereof disclosed in the present disclosure, and are not intended to exclude the possibility that one or more other features, numbers, steps, behaviors, components, parts or combinations thereof exist or are added. It should also be noted that the embodiments in the present disclosure and the features in the embodiments may be combined with each other if there is no conflict.

[0026] Figure 1 A schematic diagram of the structure of a backup power system provided in an embodiment of the present disclosure.

[0027] like Figure 1As shown, the mining flameproof battery parallel backup power system comprises a charging control module (1), a discharging control module (2), a reverse current blocking module (3), a mains voltage loss circuit (4) and a battery management system (5), wherein the voltage loss signal input end of the battery management system (5) is connected to the output end of the mains voltage loss circuit (4) to detect the mains state; the voltage acquisition line of the battery management system (5) is connected to each battery in the main power storage battery group (7) to detect the battery state; the charging control end of the battery management system (5) is connected to the charging control module (1) and the reverse current blocking module (3). The battery management system (5) is connected to the discharge control module (2) and the reverse current blocking module (3) to form a charging branch circuit, so that the main power storage battery group (7) does not supply power to the outside in the charging state; the discharge control end of the battery management system (5) is connected to the discharge control module (2) and the reverse current blocking module (3) to form a discharge branch circuit, so that the main power storage battery group (7) is not connected in parallel with the battery group of the backup power supply in the discharge state; the battery management system (5) controls the main power storage battery group (7) to charge and discharge according to the detected main power state and battery state, and controls the power supply switching between the main power and the backup power, and between the main power and the battery.

[0028] Furthermore, according to the backup power system of the embodiment of the present disclosure, when the operating voltage of some modules is different from the voltage provided by the battery pack, the backup power system may also include a battery voltage conversion module (6), one voltage input terminal of the battery voltage conversion module (6) is connected to the main power battery pack (7) through the battery switch S1, and the other voltage input terminal is connected to the backup power input terminal provided by the backup power supply, and the voltage output terminal of the battery voltage conversion module (6) is connected to the battery management system (5) to provide stable power supply to the battery management system (5), thereby ensuring that the battery management system can work normally when powered by the main power supply and the main backup power supply battery, and at the same time, it can also provide the required power supply to other loads, such as a communication control box.

[0029] Furthermore, according to the backup power system of the embodiment of the present disclosure, the backup power system also includes an inverter charger (10), and the charging and discharging ports of the inverter charger (10) are respectively connected to the charging branch and the discharging branch, thereby achieving the purpose of charging and discharging ports of the main battery (7).

[0030] The main electrical battery pack (7) in the disclosed embodiment may be a lithium-ion battery pack.

[0031] The following describes in detail the component connection relationship, working principle and specific implementation plan of the backup power system provided by the embodiment of the present disclosure in conjunction with the circuit schematic diagram.

[0032] Figure 2 A circuit schematic diagram of a backup power system provided in an embodiment of the present disclosure.

[0033] like Figure 2As shown, the backup power system in this embodiment includes a charging control module 1, a discharging control module 2, a reverse current blocking module 3, a mains voltage loss circuit 4, a battery management system (BMS) 5 and a battery voltage conversion module 6. In addition, in order to facilitate the description of the present embodiment, the figure also shows a battery pack 7 of the main power supply, a power communication control box 8, a cloud platform 9 and an inverter charging integrated machine 10.

[0034] Combine the following Figure 2 The circuit principle of the backup power system in this embodiment is described in detail.

[0035] (1.1) The charging control module 1 includes a charging control relay Q1, a charging diode D1 and a voltage loss charging control relay Q5.

[0036] Pin 1 of the normally open contact K1 of the charging control relay Q1 is connected to pin 2 of the battery switch S1, and pin 2 of the normally open contact K1 of the charging control relay Q1 is connected to the cathode of the charging diode D1; a freewheeling diode is connected in parallel at both ends of the control coil of the charging control relay Q1, pin 4 of the control coil of the charging control relay Q1 is connected to pin 1 of the charging control terminal of the BMS, and pin 3 of the control coil of the charging control relay Q1 is connected to pin 3 of the voltage output terminal of the BMS; the anode of the charging diode D1 is connected to pin 2 of the normally open contact K5 of the undervoltage charging control relay Q5; pin 2 of the normally open contact K5 of the undervoltage charging control relay Q5 is connected to the positive terminal 2 of the charging and discharging port of the inverter charging all-in-one machine 10.

[0037] (1.2) The discharge control module 2 includes a discharge control contactor Q2 and a discharge diode D2.

[0038] Pin 1 of the normally open contact K2 of the discharge control contactor Q2 is connected to pin 2 of the battery switch S1, pin 2 of the normally open contact K2 of the discharge control contactor Q2 is connected to the anode of the discharge diode D2, pin 4 of the control coil of the discharge control contactor Q2 is connected to the discharge control terminal 2 of the BMS, and pin 3 of the control coil of the discharge control contactor Q2 is connected to pin 3 of the BMS input voltage output terminal; the cathode of the discharge diode D2 is connected to the positive terminal 2 of the charging and discharging port of the inverter charger 10.

[0039] (1.3) The reverse current blocking module 3 includes a reverse drive 1, a reverse drive 2, a charging circuit breaker control contactor Q3 and a discharging circuit breaker control contactor Q4.

[0040] End 1 of the reverse drive 1 is connected to the charging control terminal 1 of the BMS, and both ends of the control coil of the charging circuit breaker control contactor Q3 are connected in parallel with a freewheeling diode; End 2 of the reverse drive 1 is connected to pin 4 of the control coil of the charging circuit breaker control contactor Q3, and pin 3 of the control coil of the charging circuit breaker control contactor Q3 is connected to pin 3 of the BMS voltage output terminal; Pin 1 of the normally open contact K3 of the charging circuit breaker control contactor Q3 is connected to pin 2 of the battery switch S1, and pin 2 of the normally open contact K3 of the charging circuit breaker control contactor Q3 is connected to BAT1+ of the main power output.

[0041] End 1 of the reverse drive 2 is connected to the discharge control end 2 of the BMS, and both ends of the control coil of the discharge circuit breaker control contactor Q4 are connected in parallel with a freewheeling diode; End 2 of the reverse drive 2 is connected to pin 4 of the control coil of the discharge circuit breaker control contactor Q4, and pin 3 of the control coil of the discharge circuit breaker control contactor Q4 is connected to pin 3 of the BMS output power supply; Pin 1 of the normally open contact K4 of the discharge circuit breaker control contactor Q4 is connected to the anode of the discharge diode D2, and pin 2 of the normally open contact K4 of the discharge circuit breaker control contactor Q4 is connected to BAT2+ of the backup power input.

[0042] (1.4) The input terminals 1 and 2 of the AC power undervoltage circuit 4 are connected to the AC power input ACN and ACL respectively; the output terminals 4 and 5 of the AC power undervoltage circuit 4 are connected to the coils 3 and 4 of the undervoltage charging control relay Q5 respectively, and the output terminal 5 of the AC power undervoltage circuit 4 is also connected to the undervoltage signal input terminal 7 of the BMA; the two ends of the control coil of the undervoltage charging control relay Q5 are connected in parallel with a freewheeling diode, and the input terminal 3 of the AC power undervoltage circuit 4 is connected to BAT- of the battery pack 7.

[0043] (1.5) The battery management system (BMS) 5 is used to monitor and manage the status of the battery pack, and includes multiple groups of voltage acquisition lines, a charging control signal terminal, a discharging control signal terminal, a voltage output terminal for outputting the power supply, a mains voltage loss signal output terminal, a communication terminal, and a power supply input terminal.

[0044] The voltage collection lines B0, B1, ..., Bn of the battery management system (BMS) 5 are connected to the electrodes of the batteries (the batteries are connected in series) in the battery pack 7 to collect the terminal voltage signal of the battery pack.

[0045] Pins 4 and 6 of the battery management system (BMS) 5 are power input terminals, wherein pin 6 is connected to BAT- of the battery pack 7, and pin 4 is connected to the voltage output pin 1 of the step-down DC / DC module 6. The battery management system (BMS) 5 obtains the stepped-down power supply energy from the step-down DC / DC module 6 through pins 4 and 6.

[0046] Pin 1 of the battery management system (BMS) 5 is a charging control signal terminal. When the terminal voltage of the battery pack 7 is lower than the set value, a low level is output, and the normally open contact K1 of the charging control relay Q1 is closed, and the charging process is started.

[0047] Pin 2 of the battery management system (BMS) 5 is a discharge control signal terminal. When the terminal voltage of the battery pack 7 is higher than the set value, a low level is output, and the normally open contact K2 of the discharge control contactor Q2 is closed, and the discharge process is started.

[0048] Pin 3 of the battery management system (BMS) 5 is a voltage output terminal, which is connected to the charging control relay Q1, the discharging control contactor Q2, the charging circuit breaker control contactor Q3 and the discharging circuit breaker control contactor Q4 respectively.

[0049] Pin 7 of the battery management system (BMS) 5 is the input terminal of the AC power undervoltage signal. When the AC power undervoltage signal is received, the K1 node of the charging control relay Q1 is quickly cut off and the K2 node of the discharge control contactor Q2 is closed, so that the battery pack 7 is quickly put into inverter.

[0050] Pin 5 of the battery management system (BMS) 5 is a communication terminal, which is connected to the power communication control box 8 .

[0051] (1.6) The battery voltage conversion module 6 is composed of universal diodes D3, D4 and a step-up / step-down D / DC module. The anode of the universal diode D3 is connected to the 2nd pin of the battery switch S1 so as to be connected to the BAT+ of the main battery pack (7). The cathode of the universal diode D3 is connected to the voltage input 2nd pin of the battery voltage conversion module 6. The battery voltage conversion module 6 can be powered by the main battery pack 7.

[0052] The anode of the universal diode D4 is connected to BAT2+ of the backup power input provided by the backup power supply, and the cathode of the universal diode D4 is connected to the voltage input 2 pin of the battery voltage conversion module 6. Thus, the battery voltage conversion module 6 can be powered by the batteries of the main and backup power supplies. When the backup power supply is not connected, the battery voltage conversion module 6 is powered by the main power battery pack 7; when the main power is not connected, the battery voltage conversion module 6 is powered by the backup power battery pack; when both the main power battery pack 7 and the backup power battery pack are connected, both of them supply power to the battery voltage conversion module 6 at the same time, and the power supply current is determined by the voltage of the main and backup power supplies, and the one with a higher voltage provides a larger current, and the one with a lower voltage provides a smaller current.

[0053] (1.7) The power communication control box 8 is the communication management center of the backup power system. It is powered by the battery voltage conversion module 6. Its communication interface exchanges information with the inverter charger 10 and the BMS 5 respectively, and is connected to the cloud platform 9 via Ethernet.

[0054] Next, combine Figure 2The working principle and process of the backup power system in this embodiment when in use are described.

[0055] The backup power system and the battery pack form a power supply system. During storage and transportation, the battery switch S1 is disconnected. When the on-site installation and commissioning are completed and the power supply system starts to work, the battery switch S1 is closed. The following describes the three situations of normal mains power supply, mains power loss and mains power recovery.

[0056] (2.1) Under normal power supply conditions, for non-online inverter chargers, they work in bypass mode and automatically switch to bypass mode, with the AC output of the inverter charger providing power to the outside; for online inverter chargers, they work in online mode, and after rectification, the input AC power is converted into stable AC power by the DC / AC inverter module, and then supplied to the outside through its AC output. At this time, the working process under several battery states is as follows.

[0057] (2.1.1) Fully charged

[0058] When the terminal voltage of the battery pack 7 is higher than the set value (generally the remaining battery power is greater than 90% of the rated capacity), the pin 1 of the BMS outputs a low level, and the contact K1 of the charging control relay Q1 is disconnected; the charging circuit formed by the charging control module 1 is disconnected, and the inverter charger 10 does not charge the battery pack 7; the reverse drive 1 of the reverse current blocking module 3 outputs a high level, and the contact K3 of the charging circuit breaker control contactor Q3 is closed; at this time, the power supply can be used as a backup DC power supply to provide battery DC backup power to the subsequent power supply through the main power output terminal.

[0059] At this time, the 2nd pin of the BMS outputs a high level, the contact K2 of the discharge control contactor Q2 is closed, and the backup battery is connected to the charging and discharging port of the inverter charger 10 through the contact K2 of the discharge control contactor Q2, providing battery backup power for the battery pack 7. At this time, due to the mains power supply, the charging and discharging port voltage of the inverter charger is close to the battery voltage. After the diode D2 is connected in series in the middle, the battery pack 7 does not discharge to the charging port. The reverse drive 1 of the reverse current blocking module 4 outputs a low level, and the contact K4 of the discharge circuit breaker control contactor Q4 is disconnected, preventing the backup battery pack from being connected in parallel with the main battery pack 7 and violating the provisions of the "Supplementary Requirements".

[0060] (2.1.2) Charging status

[0061] When the terminal voltage of the battery pack 7 is lower than the set value, the pin 1 of the BMS outputs a high level, and the contact K1 of the charging control relay Q1 is closed; the AC power undervoltage circuit 4 outputs a high level, and the contact K5 of the undervoltage charging control relay Q5 is closed; the charging circuit formed by the charging control module 1 is closed, and the inverter charger charges the battery pack 7; the reverse drive 1 of the reverse current blocking module 3 outputs a low level, and the contact K3 of the charging circuit breaker control contactor Q3 is disconnected, ensuring that the battery pack 7 does not supply power to the outside in the charging state, preventing the constant current charging curve of the inverter charger from being damaged and affecting the battery life.

[0062] At this time, the 2nd pin of the BMS outputs a low level, the contact K2 of the discharge control contactor Q2 is disconnected, and the connection between the backup battery of the battery pack 7 and the diode D2 is disconnected, that is, its discharge circuit is disconnected; the reverse drive 1 of the reverse current blocking module 4 outputs a high level, the contact K4 of the discharge circuit breaker control contactor Q4 is closed, and the backup battery voltage is connected to the charging and discharging port voltage of the inverter charger. Due to the mains power supply, the charging and discharging port voltage of the inverter charger is close to the backup battery voltage. After the diode D2 is connected in series in the middle, the backup battery pack does not discharge to the charging port of the inverter charger and is in a static state, preventing the backup battery pack from being connected in parallel with the main battery pack 7 and violating the provisions of the "Supplementary Requirements".

[0063] (2.1.3) Full conversion state

[0064] When the terminal voltage of the storage battery group 7 is charged to the set value, the contact K1 of the charging control relay Q1 is disconnected, the charging process ends, and the DC backup power function for the subsequent load is restored.

[0065] Therefore, when there is AC power, when the battery is in the fully charged state, charging state and full conversion state, the backup power system will not violate the provisions of the "Supplementary Requirements", nor will it destroy the constant current charging curve of the charging and discharging port of the inverter charger, and will not have the impact of shortening the battery life.

[0066] (2.2) When the AC power fails, the AC power failure circuit 4 outputs a low level, the contact K5 of the failure charging control relay Q5 is disconnected, and the charging circuit is disconnected. At this time, there are the following two situations.

[0067] (2.2.1) The battery pack 7 is fully charged and outputs normally, and the inverter charging and discharging integrated machine is inverting and outputting.

[0068] At this time, when the terminal voltage of the battery pack 7 is higher than the set value, the pin 1 of the BMS outputs a low level, the contact K1 of the charging control relay Q1 is disconnected, and the charging circuit formed by the charging control module 1 is disconnected; the pin 2 of the BMS outputs a high level, the contact K2 of the discharge control contactor Q2 is closed, and the backup battery is connected to the charging and discharging port of the inverter charger through the contact K2 of the discharge control contactor Q2 to provide battery backup power for the battery pack 7. At this time, due to the loss of mains voltage, the charging and discharging port voltage of the inverter charger is lower than the battery voltage, the series diode D2 is turned on, the battery pack 7 is discharged through the charging and discharging port, and the inverter charger inverts and outputs AC power.

[0069] The reverse drive 1 of the reverse current blocking module 3 outputs a high level, and the contact K3 of the charging circuit breaker control contactor Q3 is closed. At this time, the battery pack 7 can also be used as a backup DC power supply to provide battery DC backup power for the subsequent power supply through the main power output terminal.

[0070] The inverting drive 2 of the reverse current blocking module 3 outputs a low level, and the contact K4 of the discharge circuit breaker control contactor Q4 is disconnected, preventing the backup battery pack from being connected in parallel with the main battery pack 7 and violating the provisions of the "Supplementary Requirements".

[0071] (2.2.2) The battery pack 7 runs out of power and cuts off output, and the backup battery inverts the output.

[0072] After the battery pack 7 is discharged, the battery voltage will continue to decrease. When the terminal voltage of the battery pack 7 is lower than the set value, the 2nd pin of the BMS outputs a low level, the contact K2 of the discharge control contactor Q2 is disconnected, and the connection between the backup battery of the battery pack 7 and the diode D2 is disconnected, that is, the discharge circuit of the battery pack 7 is disconnected. The reverse drive 1 of the reverse current blocking module 4 outputs a high level, the contact K4 of the discharge circuit breaker control contactor Q4 is closed, and the backup battery voltage is connected to the charging and discharging port voltage of the inverter charger. At this time, due to the loss of mains voltage, the charging and discharging port voltage of the inverter charger is lower than the backup battery voltage, the diode D2 is turned on, the backup battery discharges to the charging port of the inverter charger, and the inverter charger outputs AC power. Since the contacts K1, K2 and K5 are disconnected, only the backup battery is connected to the charging and discharging port of the inverter charger, so the backup battery is not connected in parallel with the main battery pack 7, and will not violate the provisions of the "Supplementary Requirements".

[0073] While the BMS pin 2 outputs a low level, the BMS pin 1 outputs a high level, and the contact K1 of the charging control relay Q1 is closed. However, due to the loss of mains voltage, the mains voltage loss circuit 4 outputs a low level, and the contact K5 of the voltage loss charging control relay Q5 is disconnected; the charging circuit formed by the charging control module 1 is disconnected, and the inverter charger does not charge the battery pack 7. The reverse drive 1 of the reverse current blocking module 3 outputs a low level, and the contact K3 of the charging circuit breaker control contactor Q3 is disconnected, preventing the battery pack 7 from discharging to the outside in the charging state and causing battery damage.

[0074] (2.2.3) When the backup battery runs out of power, the backup power output circuit will be automatically cut off to avoid over-discharge and damage to the battery.

[0075] (2.3) Mains power supply is restored

[0076] (2.3.1) When the battery pack 7 is discharged, after the AC power is restored, the inverter charger switches to the AC power supply state; the AC power loss circuit 4 outputs a high level, and the contact K5 of the loss-of-voltage charging control relay Q5 is closed. If the BMS detects that the remaining power of the battery pack 7 is greater than or equal to 90% of its capacity, the contact K1 of the charging control relay Q1 is disconnected; at this time, the power supply is restored to the fully charged operating state mentioned above (2.1.1), and the battery pack 7 is in a static state.

[0077] (2.3.2) Discharge of backup power supply battery pack

[0078] At this time, the inverter charger switches to the AC power supply state, the battery pack 7 is in an undervoltage state, and the contact K1 of the charging control relay Q1 is also closed. At the same time, the AC power undervoltage circuit 4 outputs a high level, and the contact K5 of the undervoltage charging control relay Q5 is closed. The power supply returns to the aforementioned charging operation state (2.1.2).

[0079] (2.3.3) Recharging process of battery pack 7

[0080] After the mains power is restored, the contact K5 of the voltage-loss charging control relay Q5 is closed. If the BMS detects that the remaining power of the battery pack 7 is greater than or equal to 90% of its capacity, the contact K1 of the charging control relay Q1 is closed. At this time, the power supply is in the charging state, that is, it is restored to the charging operation state mentioned above (2.1.2).

[0081] Therefore, in each of the operating states (2.1), (2.2) and (2.3) mentioned above, the backup battery will not be connected in parallel with the main battery pack 7, and the provisions of the "Supplementary Requirements" will not be violated; when charging, it can also be ensured that the charging circuit is only connected by the charged battery and the charging and discharging port of the charging and discharging integrated machine, and the charging curve of the battery will not be damaged.

[0082] Next, combine Figure 2 The battery switching process of the backup power system in this embodiment when in use is described.

[0083] When using the backup power system, the battery switching is divided into the following three situations: a. From the normal mains power to the mains power loss, if the main battery is fully charged, switch to the main battery for power supply; b. From the normal mains power to the mains power loss, if the main battery is half charged, switch to the battery for power supply; c. After the battery is fully discharged, the backup power battery is used for power supply. When using the backup power system provided by the present invention, during the inverter process of converting the mains power to the battery, the battery is put into use quickly and will not affect the normal operation of the subsequent load. The above three situations are explained below.

[0084] (3.1) When the city power is normal, when the battery pack 7 is fully charged (i.e., the remaining capacity of the battery is greater than 90% of its rated capacity), the 2nd pin of the BMS outputs a high level, the contact K2 of the discharge control contactor Q2 is closed, and the positive electrode of the battery pack 7 is connected to the positive electrode of the charging and discharging port of the inverter charger 10 through the contact K2 via the discharge diode D2. When the city power loses voltage, the inverter charger 10 switches to the battery inverter mode, the voltage of the battery pack 7 is higher than the voltage of the positive electrode of the charging and discharging port of the inverter charger 10, the discharge diode D2 applies a forward voltage, the discharge diode D2 is forward-conducted, and the electric energy of the battery pack 7 is inverted and output as AC power through the inverter charger 10. The discharge circuit of the battery pack 7 is always connected, and the discharge switching time is the diode conduction time, and the diode forward conduction time is very short, only a few hundred nanoseconds, so the switching time in this case is extremely short and does not affect the load operation.

[0085] (3.2) When the mains power is normal, when the battery pack 7 is not fully charged (i.e., the remaining capacity of the battery is less than 90% of its rated capacity), the pin 1 of the BMS outputs a high level, the contact K1 of the charging control contactor Q1 is closed, and the charging circuit of the battery pack 7 is closed; the pin 2 of the BMS outputs a low level, the contact K2 of the discharge control contactor Q2 is disconnected, and the discharge circuit of the battery pack 7 is disconnected. When the mains power loses pressure, the inverter charger 10 switches to the battery inverter mode. After receiving the mains power loss signal, the mains power loss signal input terminal 7 of the BMS quickly controls the contact K1 of the charging control contactor Q1 to be disconnected and the contact K2 of the discharge control contactor Q2 to be closed, and the battery pack 7 quickly switches from the charging state to the discharging state.

[0086] In the scheme of the embodiment of the present disclosure, the contactors are all DC contactors, and DC contactors generally have only normally open points, and the action time is generally less than the release time. Therefore, the above-mentioned discharge control contactor Q2 contact K2 closes before the charge control contactor Q1 contact K1 opens, so that the positive electrode of the battery pack 7 and the positive electrode 2 of the charging and discharging port of the inverter charger 10 are seamlessly connected in time, and the switching time is the delay of the AC undervoltage circuit 4 generating the AC undervoltage signal and the delay of the BMS receiving the AC undervoltage signal and generating a control action. These circuits are composed of resistors, capacitors and transistor circuits, and the delay can be very short (about a few hundred nanoseconds). Therefore, the switching time in this case is extremely short and does not affect the load operation.

[0087] (3.3) When the main power supply loses voltage and the main power battery pack 7 is exhausted, the discharge control terminal 2 of the BMS outputs a low level, controls the quick control discharge control contactor Q2 to disconnect the contact K2, and at the same time, controls the contact K4 of the discharge circuit breaker control contactor Q4 to close through the reverse drive 2, and the charging inverter 10 is powered by the battery pack of the backup power supply. The discharge control contactor Q2 and the discharge circuit breaker control contactor Q4 are the same type of contactors, and their action time is generally less than the release time. Therefore, the contact K4 of the discharge circuit breaker control contactor Q4 closes before the contact K2 of the discharge control contactor Q2 disconnects. The switching time is the delay of the BMS detecting the remaining power of the battery pack 7 and generating a discharge control signal. These circuits are composed of resistors, capacitors, transistors, integrated circuits and CPUs, and the delay can be very short (about hundreds of nanoseconds). Therefore, the switching time in this case is also very short and does not affect the load operation.

[0088] The working principle of the backup power system provided by the embodiment of the present disclosure has been described above. A specific embodiment is given below for the selection of components in the backup power system circuit.

[0089] (4.1) Charging control module

[0090] The key to the implementation of the charging control module 1 is the selection of the charging control relay Q1, the charging diode D1 and the charging control relay Q5. Since the charging current is generally 3A to 5A, a DC relay with a contact capacity equivalent to it and a relay coil voltage of 24V is used. The charging control relay Q1 and the charging control relay Q5 can be selected from SMIA-SH-224DM of Sanyou Lianzhong, and its contact capacity is: 10A, 110V. The charging diode D1 can be selected from Luguang Electronics SD10U150SL, and the main parameters are: reverse voltage of 150V, rectified current of 10A, and forward conduction voltage drop of 790mA@10A.

[0091] (4.2) Discharge control module

[0092] The key to the implementation of the discharge control module 2 is the selection of the discharge control contactor Q2 and the discharge diode D2. In this embodiment, the inverter output capacity of the inverter charging and discharging machine is 2KVA, and the rated voltage of the battery pack 7 is 72V. Therefore, the rated output current of the battery pack 7 is about 27.8A. Therefore, the DC contactor HFE80V-40 of Hongfa Electroacoustics can be selected, and its main parameters are: contact capacity DC450, 40A, and coil voltage: DC24V. The discharge diode D2 uses Yangjie Electronics' MBR40150PT, and its main parameters are: reverse voltage 150V, forward conduction current 40A.

[0093] (4.3) Reverse current blocking module

[0094] The circuit principle of the reverse current blocking module 3 is as follows Figure 3 As shown, it is composed of reverse drive 1 (31), reverse drive 2 (32), charging circuit breaker control contactor Q3 and discharging circuit breaker control contactor Q4.

[0095] The reverse drive 1 (31) is composed of a resistor R7, a resistor R8 and a driving MOS tube T1 (model SI2318).

[0096] Pin 1 of resistor R7 is connected to the charging control signal terminal 1 of the battery management system (BMS), and pin 2 of resistor R7 is connected to the gate of the driving MOS tube T1. Pins 1 and 2 of resistor R8 are connected to the gate and source of MOS tube T1 respectively. The source of MOS tube T1 is connected to the negative electrode BAT- of the battery pack 7, and the common end of the drain of MOS tube T1 and pin 2 of resistor R8 is connected to pin 4 of the coil of the charging circuit breaker control contactor Q3. Resistors R7 and R8 form a voltage divider circuit, which divides the charging control signal terminal of the BMS and drives MOS tube T1 to control the contact of the charging circuit breaker control contactor Q3 to achieve isolation between the main power supply and the backup power supply when charging, so as to avoid damaging the charging process of the main power supply.

[0097] The reverse drive 2 (32) is composed of a gate resistor R9, a resistor R10 and a driving MOS tube T2 (model SI2318).

[0098] Pin 1 of resistor R9 is connected to the discharge control signal terminal 2 of the battery management system (BMS), and pin 2 of resistor R9 is connected to the gate of the driving MOS tube T2. Pins 1 and 2 of resistor R10 are connected to the gate and source of MOS tube T2 respectively. The source of MOS tube T2 is connected to the negative electrode BAT- of the battery pack 7, and the common end of the drain of MOS tube T2 and pin 2 of resistor R10 is connected to pin 4 of the coil of the discharge circuit breaker control contactor Q4. Resistors R9 and R10 form a voltage divider circuit, which divides the discharge control signal terminal of BMS and drives MOS tube T2 to control the contact of the charging circuit breaker control contactor Q4 to achieve isolation between the main power supply and the backup power supply when discharging, so as to avoid the situation where the main and backup power batteries are connected in parallel when the main power supply is discharged, thereby violating the provisions of the "Supplementary Requirements".

[0099] (4.4) Mains voltage loss circuit

[0100] The circuit principle of the mains voltage loss circuit 4 is as follows Figure 4 As shown, the mains voltage loss circuit 4 is composed of a resistor RZ1, a rectifier bridge Z1, a capacitor CZ1, a resistor Rs1, a resistor Rs2 and a photocoupler GDs.

[0101] The hot end (high voltage side) of the mains voltage loss circuit 4 is the resistor RZ1, the rectifier bridge Z1, the capacitor CZ1, the resistor Rs1 and the light emitting diode of the photocoupler GDs. Pin 1 of the resistor RZ1 is connected to the mains ACL terminal, the pin 1 of the voltage drop resistor RZ1 is connected to the pin 1 of the rectifier bridge Z1, and the pin 2 of the rectifier bridge Z1 is connected to the mains ACN terminal. The capacitor CZ1 is connected in parallel to the pins 3 and 4 of the rectifier bridge Z1. Pin 1 of the resistor Rs1 is connected to the pin 4 of the rectifier bridge Z1, the pin 2 of the resistor Rs1 is connected to the pin 1 (anode of the light emitting diode) of the photocoupler GDs, and the pin 2 (cathode of the light emitting diode) of the photocoupler GDs is connected to the pin 3 of the rectifier bridge Z1.

[0102] The cold end (low voltage side) of the mains voltage loss circuit 4 is the resistor Rs2 and the photosensitive triode of the photocoupler GDs. Pin 1 of the resistor Rs2 is connected to pin 4 of the photocoupler GDs, and pin 2 of the resistor Rs2 is connected to the power supply VCC. Pin 3 of the photocoupler GDs is connected to the negative electrode BAT- of the power system, and pin 4 of the photocoupler GDs is the mains voltage loss signal output terminal SY.

[0103] The rectifier filter circuit composed of resistor RZ1, rectifier bridge Z1 and capacitor CZ1 rectifies the mains into a DC signal, which drives the light-emitting diode of the photocoupler GDs to emit light after the current is limited by resistor Rs1. The photosensitive triode of the photocoupler GDs turns on after receiving the light and generates a mains voltage loss control signal.

[0104] The selection of photocoupler GDs is the key. Considering that the coil drive current of charging control relay Q5 is 20-60mA, a photocoupler with collector current Ic>100mA is selected, such as TLP127GB-S of UMW Semiconductor.

[0105] The input filter circuit composed of resistor RZ1, rectifier bridge Z1 and capacitor CZ1 has a time constant of less than 5mS, which can quickly respond to the mains voltage loss signal and output the control signal within a quarter of the mains cycle. When the mains voltage is lost, the BMS quickly controls the charging control relays Q1 and Q2 and the discharge control contactor Q2, and switches to the battery pack 7 to supply power to the inverter charger.

[0106] (4.5) Battery Management System (BMS)

[0107] The battery management system (BMS) 5 can use Hangzhou Gote's BMS3612, which supports 36-channel voltage detection, 16-channel temperature detection, and AC power loss signal control, and can meet the use requirements of the backup power system in the embodiment of the present disclosure.

[0108] (4.6) Battery voltage conversion module

[0109] The battery voltage conversion module 6 is composed of universal diodes D3, D4 and a step-up / step-down D / DC module. The step-up / step-down DC / DC module 6 adopts a step-down solution. Since the coil operating voltages of the charging control relay Q1, the discharging control contactor Q2, the charging circuit breaker control contactor Q3, the discharging circuit breaker control contactor Q4 and the charging control relay Q5 are all 24V, and the rated terminal voltage of the battery pack 7 is 72V, a step-down DC / DC solution is adopted. The corresponding circuit principle is as follows: Figure 5 shown.

[0110] The step-down circuit can use the DC / DC chip MP9486A of MPS (Core Source). The working principle of the circuit is briefly described below: Figure 5 As shown, capacitors C1 and C2 are input capacitors and are connected to the power input terminal to play the role of input filtering; resistor R4 is connected to the voltage input terminal VIN and pin 6 of MP9486A to enable chip MP9486A; inductor L1, diode D1, capacitor C6 and MP9486A form a BUCK circuit to generate output voltage; R1 and R2 form an output voltage divider feedback circuit to control the output voltage amplitude, and the adjusted voltage divider ratio can adjust the output voltage; capacitors C1 and C2 are output capacitors and are connected to the power output terminal to play the role of output filtering.

[0111] (4.7) Battery pack

[0112] The battery pack 7 can be a lithium ion, lead acid, nickel-chromium, etc. In this embodiment, lithium ion batteries are used, and 24 strings of 3.2V 100AH ​​lithium iron phosphate battery packs can be used, and the maximum output power meets the output power requirements of the power supply system.

[0113] In summary, the solution provided by the embodiment of the present disclosure adopts a DC relay, a DC contactor, a high-power diode, a battery management system, a mains voltage loss circuit and a related reverse drive circuit, which solves the problem of parallel backup power supply of the main and backup power supplies under the condition of mains voltage loss, and also meets the safety standard requirements that battery parallel backup power supply must meet. This solution not only meets market demand, but also has the advantages of simple structure, low cost, easy production and installation and commissioning, and has good technical effects and economic benefits.

[0114] Based on the same inventive concept, the present disclosure also provides a mine flameproof battery power supply, which is suitable for parallel use with a backup power supply. The power supply includes: the mine flameproof backup power system as described above, the backup power system is provided with a battery cavity, and a battery pack arranged in the battery cavity. The battery pack can be a lithium-ion battery, such as a 24-series 3.2V 100AH ​​lithium iron phosphate battery pack, and the maximum output power meets the output power requirements of the power supply system. The power supply can also have intrinsic safety performance, becoming a mine flameproof and intrinsically safe lithium-ion battery power supply, so as to adapt to more stringent application environments.

[0115] The above description is only an embodiment of the present disclosure and is not intended to limit the present disclosure. For those skilled in the art, the present disclosure may have various changes and variations. Any modification, equivalent substitution, improvement, etc. made within the spirit and principle of the present disclosure shall be included in the scope of the claims of the present disclosure.

Claims

1. A mining flameproof battery parallel backup power system, characterized in that: It comprises a charging control module (1), a discharging control module (2), a reverse current blocking module (3), a mains voltage loss circuit (4) and a battery management system (5), wherein: The voltage loss signal input end of the battery management system (5) is connected to the output end of the mains voltage loss circuit (4) to detect the mains power state; The voltage collection line of the battery management system (5) is connected to each battery in the main battery pack (7) to detect the battery status; The charging control terminal of the battery management system (5) is connected to the charging control module (1) and the reverse current blocking module (3) to form a charging branch circuit, so that the main power storage battery group (7) does not supply power to the outside in a charging state; The discharge control terminal of the battery management system (5) is connected to the discharge control module (2) and the reverse current blocking module (3) to form a discharge branch circuit, so that the main power storage battery group (7) is not connected in parallel with the battery of the backup power supply in the discharge state; The battery management system (5) controls the charging and discharging of the main power storage battery pack (7) and controls the power supply switching between the main power and the backup power, and between the main power and the battery, based on the detected main power status and the battery status, using the charging branch and the discharging branch.

2. The backup power system according to claim 1, characterized in that: The backup power system further comprises a battery voltage conversion module (6), one voltage input end of the battery voltage conversion module (6) being connected to the main power storage battery pack (7) via a battery switch S1, and the other voltage input end being connected to the backup power input end provided by the backup power supply, and the voltage output end of the battery voltage conversion module (6) being connected to the battery management system (5) to provide stable power supply to the battery management system (5).

3. The backup power system according to claim 2, characterized in that: The battery voltage conversion module (6) comprises a universal diode D3, a universal diode D4 and a step-up / step-down DC / DC module, wherein: The anode of the universal diode D3 is connected to BAT+ of the main battery pack (7) through the battery switch S1, and the cathode of the universal diode D3 is connected to the voltage input terminal of the step-up / step-down DC / DC module; the anode of the universal diode D4 is connected to BAT2+ of the backup power input provided by the backup power supply, and the cathode of the universal diode D4 is connected to the voltage input terminal of the step-up / step-down DC / DC module.

4. The backup power system according to claim 1, characterized in that: The backup power system further comprises an integrated inverter charger (10), wherein the charging and discharging ports of the integrated inverter charger (10) are respectively connected to the charging branch and the discharging branch.

5. The backup power system according to claim 4, characterized in that: The charging control module (1) comprises a charging control relay Q1, a charging diode D1 and a voltage-loss charging control relay Q5, wherein: The two electric pins of the normally open contact K1 of the charging control relay Q1 are respectively connected to the cathode of the battery switch S1 and the charging diode D1; the two ends of the control coil of the charging control relay Q1 are respectively connected to the charging control end and the voltage output end of the battery management system (5); the two electric pins of the normally open contact K5 of the undervoltage charging control relay Q5 are respectively connected to the anode of the charging diode D1 and the positive end of the charging and discharging port of the inverter charging integrated machine (10); the two ends of the control coil of the undervoltage charging control relay Q5 are respectively connected to the two output ends of the mains undervoltage circuit (4).

6. The backup power system according to claim 4, characterized in that: The discharge control module (2) comprises a discharge control contactor Q2 and a discharge diode D2, wherein: The two electric pins of the normally open contact K2 of the discharge control contactor Q2 are respectively connected to the anode of the battery switch S1 and the discharge diode D2; the two ends of the control coil of the discharge control contactor Q2 are respectively connected to the discharge control end and the voltage output end of the battery management system (5); the cathode of the discharge diode D2 is connected to the positive end of the charging and discharging port of the inverter charger (10).

7. The backup power system according to claim 6, characterized in that: The reverse current blocking module (3) comprises an inverting drive circuit 1, an inverting drive circuit 2, a charging circuit breaker control contactor Q3 and a discharging circuit breaker control contactor Q4, wherein: The input end of the reverse drive circuit 1 is connected to the charging control end of the battery management system (5); the output end of the reverse drive circuit 2 is connected to one electric pin of the control coil of the charging circuit breaker control contactor Q3; the other electric pin of the control coil of the charging circuit breaker control contactor Q3 is connected to the voltage output end of the battery management system (5); the two electric pins of the normally open contact K3 of the charging circuit breaker control contactor Q3 are respectively connected to the battery switch S1 and the main power output BAT1+, The input end of the reverse drive circuit 2 is connected to the discharge control end of the battery management system (5); the output end of the reverse drive circuit 2 is connected to one electric pin of the control coil of the discharge circuit breaker control contactor Q4; the other electric pin of the control coil of the discharge circuit breaker control contactor Q4 is connected to the voltage output end of the battery management system (5); and the two electric pins of the normally open contact K4 of the discharge circuit breaker control contactor Q4 are respectively connected to the anode of the discharge diode D2 and the backup power input BAT2+.

8. The backup power system according to claim 1, characterized in that: The two input ends of the mains voltage loss circuit (4) are connected to the mains input ACN and ACL respectively, and the third input end of the mains voltage loss circuit (4) is connected to BAT- of the main battery pack (7).

9. The backup power system according to claim 8, characterized in that: The mains voltage loss circuit (4) comprises a filter circuit, a light emitting element and a photosensitive element. The filter circuit rectifies the mains into a direct current signal to drive the light emitting element to emit light, and the photosensitive element receives light to generate a mains voltage loss control signal.

10. The backup power system according to claim 1, characterized in that: The main battery pack (7) is a lithium-ion battery pack.

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