Disclosure of Invention
Aiming at the defects in the prior art, the invention provides a BMS high-side detection charging and discharging circuit to provide a technology for disconnecting a high-side MOS direct current charger and an electronic load detection, so that damage to equipment is avoided, the use safety of a user is improved, the working efficiency is improved, and the operation and maintenance installation cost is reduced.
The invention provides a BMS high-side detection charge-discharge circuit, comprising:
the discharge control switch tube is electrically connected with the positive electrode of the battery pack and is connected with a discharge control signal, and the negative electrode of the battery pack is grounded;
The charging control switch tube is electrically connected with the discharging control switch tube and is connected with a charging control signal;
The load detection circuit is electrically connected with the charging control switch tube and is used for detecting a load access signal;
The analog load access switch circuit is connected with the charge control switch tube and the load detection circuit together and is used for switching in or switching off the analog load;
The analog charger access switch circuit is connected with the charging control switch tube, the load detection circuit and the analog load access switch circuit together and is used for switching on or switching off the analog charger;
The charging detection circuit is connected with the charging control switch tube, the load detection circuit, the analog load access switch circuit and the analog charger access switch circuit together and is used for detecting a charger access signal;
when the discharging control switch tube and the charging control switch tube are disconnected and the analog load access switch circuit is conducted, the load detection circuit detects the load access signal; when the discharging control switch tube is disconnected and the analog charger access switch circuit is conducted, the charging detection circuit detects the charger access signal.
Further, the discharging control switch tube comprises a MOS tube Q3A, the drain electrode of the MOS tube Q3A is connected with the positive electrode of the battery pack, the grid electrode of the MOS tube Q3A is connected with a discharging control signal, and the source electrode of the MOS tube Q3A is electrically connected with the charging control switch tube.
Further, the charging control switch tube comprises a MOS tube Q2A, a source electrode of the MOS tube Q2A is connected with a source electrode of the MOS tube Q3A, a grid electrode of the MOS tube Q2A is connected with a charging control signal, a drain electrode of the MOS tube Q2A is connected with the charging detection circuit, and the load detection circuit, the analog load access switch circuit and the analog charger access switch circuit are connected together.
Further, the load detection circuit comprises a resistor R10, a resistor R1, a diode D2 and a diode D1; the power supply VCC is connected with the first end of the resistor R10, the second end of the resistor R10 is commonly connected with the first end of the resistor R1 and the anode of the diode D2, and the second end of the resistor R1 outputs a detected load access signal to the MCU of the BMS; the anode of the diode D1 is connected with the cathode of the diode D2, and the cathode of the diode D1 is commonly connected with the drain electrode of the MOS tube Q2A, the charging detection circuit, the analog load access switch circuit and the analog charger access switch circuit.
Further, the level of the resistor R10 defaults to a high level.
Further, the analog load access switch circuit comprises an analog load access switch J1, a resistor RL and a resistor R2; one end of the analog load access switch J1 is connected with the cathode of the diode D1, the drain electrode of the MOS tube Q2A, the charging detection circuit and the analog charger access switch circuit together, the other end of the analog load access switch J is connected with the first end of the resistor RL, the second end of the resistor RL is connected with the first end of the resistor R2, and the second end of the resistor R2 is grounded; when the discharging control switch tube and the charging control switch tube are disconnected and the analog load access switch J1 is closed, the analog load access switch circuit is conducted, and the load detection circuit detects a load access signal.
Further, the analog charger access switch circuit comprises an analog charger access switch J2 and a charging power supply Charg, one end of the analog charger access switch J2 is connected with the drain electrode of the MOS tube Q2A, the charging detection circuit, the analog load access switch circuit and the load detection circuit together, the other end of the analog charger access switch circuit is connected with the positive electrode of the charging power supply Charg, and the negative electrode of the charging power supply Charg is grounded.
Further, the charging detection circuit comprises a resistor R3, a resistor R4, a resistor R5, a resistor R6, a resistor R7 and a triode Q1; the first end of the resistor R4 is connected with the drain electrode of the MOS tube Q2A, the analog load access switch circuit, the load detection circuit and the analog charger access switch circuit together, and the second end of the resistor R4 is connected with the first end of the resistor R3 and the first end of the resistor R5 together; the second end of the resistor R3 is connected with the base electrode of the triode Q1, and the second end of the resistor R5 is grounded; the collector of triode Q1 connects the first end of resistance R6 and the first end of resistance R7, and power VCC is connected to resistance R6's second end, and resistance R7's second end output the charger access signal of detecting gives the MCU to BMS.
Further, the level of the resistor R6 defaults to a high level.
Further, the discharging control switch tube is controlled to be disconnected by the discharging control signal when the discharging control switch tube is overdischarged, and the charging control switch tube is controlled to be disconnected by the charging control signal when the charging control switch tube is overcharged.
Compared with the prior art, the invention has the following beneficial effects:
The invention provides a BMS high-side detection charge-discharge circuit, which comprises a discharge control switch tube, a charge control switch tube, a load detection circuit, an analog load access switch circuit, an analog charger access switch circuit and a charge detection circuit, wherein the discharge control switch tube is electrically connected with the positive electrode of a battery pack and is accessed into a discharge control signal, the negative electrode of the battery pack is grounded, the charge control switch tube is electrically connected with the discharge control switch tube and is accessed into the charge control signal, the load detection circuit is electrically connected with the charge control switch tube and is used for detecting a load access signal, the analog load access switch circuit is commonly connected with the charge control switch tube and the load detection circuit and is used for analog load access or disconnection, the analog charger access switch circuit is commonly connected with the charge control switch tube, the load detection circuit and the analog load access switch circuit, the charging detection circuit is connected with the charging control switch tube, the load detection circuit, the analog load access switch circuit and the analog charger access switch circuit together and is used for detecting a charger access signal, when the discharging control switch tube and the charging control switch tube are disconnected and the analog load access switch circuit is conducted, the load detection circuit detects the load access signal, when the discharging control switch tube is disconnected and the analog charger access switch circuit is conducted, the charging detection circuit detects the charger access signal, thereby realizing the disconnection of a high-side MOS (metal oxide semiconductor) direct-current charger and the electronic load detection, avoiding the damage to equipment, increasing the use safety of users and improving the working efficiency, and the operation and maintenance installation cost is reduced.
Detailed Description
In order to enable those skilled in the art to better understand the present invention, the following description will make clear and complete descriptions of the technical solutions according to the embodiments of the present invention with reference to the accompanying drawings. It will be apparent that the described embodiments are merely some, but not all embodiments of the invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the present invention without making any inventive effort, shall fall within the scope of the present invention.
Referring to fig. 1-2, an embodiment of the present invention provides a BMS high side detection charge-discharge circuit, including:
The discharging control switch tube 100 is electrically connected with the positive electrode of the battery pack 105, and is connected with a discharging control signal, and the negative electrode of the battery pack 105 is grounded;
a charge control switch tube 101 electrically connected with the discharge control switch tube 100 and connected with a charge control signal;
the load detection circuit 102 is electrically connected with the charging control switch tube 101 and is used for detecting a load access signal;
The analog load access switch circuit 103 is connected with the charge control switch tube 101 and the load detection circuit 102 together and is used for switching on or switching off an analog load;
An analog charger access switch circuit 104, which is connected with the charge control switch tube 101, the load detection circuit 102 and the analog load access switch circuit 103 together, and is used for switching on or switching off the analog charger;
a charging detection circuit 106, connected to the charging control switch 101, the load detection circuit 102, the analog load access switch circuit 103, and the analog charger access switch circuit 104, for detecting a charger access signal;
When the discharging control switch tube 100 and the charging control switch tube 101 are disconnected and the analog load access switch circuit 103 is connected, the load detection circuit 102 detects the load access signal; when the discharge control switch tube 100 is turned off and the analog charger access switch circuit 104 is turned on, the charge detection circuit 106 detects the charger access signal.
It should be noted that, in this embodiment, when the discharging control switch tube 100 and the charging control switch tube 101 are turned off, and the analog load access switch circuit 103 is turned on, the load detection circuit 102 detects the load access signal, and when the discharging control switch tube 100 is turned off, and the analog charger access switch circuit 104 is turned on, the charging detection circuit 106 detects the charger access signal, thereby realizing the disconnection of the high-side MOS dc charger and the electronic load detection, avoiding the damage to the equipment, increasing the safety of the user, improving the working efficiency, and reducing the operation and maintenance installation cost.
In this embodiment, the load and charger access switch circuit may simulate the access conditions of the actual load and charger, so as to detect the load and charger access signals, and improve the detection accuracy and safety of the system.
It should be noted that the battery pack 105 may be formed by connecting a plurality of batteries in series or in parallel. For example, the battery pack 105 is formed by connecting the battery B1, the battery B2, the battery B3, the battery B4, and the battery B5 in series.
It should be noted that the discharge control switching tube (MOS tube Q3A) and the charge control switching tube (MOS tube Q2A) both belong to high-side switching tubes. The high-side switching tubes are respectively connected between the positive electrode of the battery and the load and between the positive electrode of the battery and the charger, and the charge and discharge paths of the battery can be managed by controlling the on and off of the high-side switching tubes. Meanwhile, the load detection circuit and the charging detection circuit are also arranged on the high side, and the access condition of the load and the charger can be detected by monitoring the state of the high-side switch, so that the safe and reliable operation of the circuit is ensured.
In some preferred embodiments, the discharging control switch tube 100 includes a MOS tube Q3A, a drain electrode of the MOS tube Q3A is connected to the positive electrode of the battery pack 105, a gate electrode of the MOS tube Q3A is connected to a discharging control signal, and a source electrode of the MOS tube Q3A is electrically connected to the charging control switch tube 101. The charging control switch tube 101 comprises a MOS tube Q2A, a source electrode of the MOS tube Q2A is connected with a source electrode of the MOS tube Q3A, a grid electrode of the MOS tube Q2A is connected with a charging control signal, a drain electrode of the MOS tube Q2A is connected with the charging detection circuit 106, and the load detection circuit 102, the analog load access switch circuit 103 and the analog charger access switch circuit 104 are connected together.
The discharging control switch tube 100 (MOS tube Q3A) is connected to the positive electrode of the battery pack 105, and the gate is connected to a discharging control signal, so that when the discharging control signal turns on Q3A, the electric energy of the battery pack 105 can flow to the load through Q3A. The source of the charge control switch tube 101 (MOS tube Q2A) is connected to the source of the MOS tube Q3A, the gate is connected to a charge control signal, and when the charge control signal turns on Q2A, a charge current can flow to the battery pack 105 through Q2A. When the MOS tube Q3A, MOS tube Q2A is disconnected and the analog load access switch circuit 103 is switched on, the load detection circuit 102 detects the load access signal, when the MOS tube Q3A is disconnected and the analog charger access switch circuit 104 is switched on, the charge detection circuit 106 detects the charger access signal, so that the high-side MOS direct-current charger and the electronic load detection are disconnected, damage to equipment is avoided, the use safety of a user is improved, the working efficiency is improved, and the operation and maintenance installation cost is reduced.
In some preferred embodiments, the load detection circuit 102 includes a resistor R10, a resistor R1, a diode D2, and a diode D1; the power supply VCC is connected with the first end of the resistor R10, the second end of the resistor R10 is commonly connected with the first end of the resistor R1 and the anode of the diode D2, and the second end of the resistor R1 outputs a detected load access signal to the MCU of the BMS; the anode of the diode D1 is connected to the cathode of the diode D2, and the cathode of the diode D1 is commonly connected to the drain of the MOS transistor Q2A, the charge detection circuit 106, the analog load access switch circuit 103, and the analog charger access switch circuit 104. Wherein the level through resistor R10 defaults to a high level.
In the present embodiment, the load detection circuit 102 is implemented by the resistor R10, the resistor R1, the diode D2, and the diode D1, and when the power VCC supplies the resistor R1 with a high level through the resistor R10, the load detection circuit 102 is at a high level. When the analog load access switch circuit 103 is turned on, the level of the resistor R10 is pulled down by the load, and the load detection circuit 102 outputs a low level signal to the MCU of the BMS, indicating that the load access is detected. In this embodiment, the load detection circuit 102 is implemented by a simple resistor and diode, and has a simple structure and low cost. In addition, the load detection circuit 102 realizes the detection of the load access signal through the level change, and improves the detection sensitivity and reliability of the system.
It should be noted that the diode D2 functions to block the reverse current under normal conditions (i.e., no load is connected). Because the diode is only turned on unidirectionally, diode D2 prevents current from flowing back from the port of resistor R1, ensuring that resistor R1 is maintained at the desired voltage level. Diode D1 further protects the circuit. When the MOS transistor Q2A is turned on and a reverse current occurs, the diode D1 can prevent the current from directly affecting the load detection circuit 102. The diode D2 keeps the resistor R1 at a high level through the resistor R10 under the high level condition, so as to ensure that the load detection signal is kept stable under the normal operating state. After diode D1 is connected in series with diode D2, the change in level is more pronounced when the load access signal is detected. The combination of the diode D1 and the diode D2 makes the level change difference more obvious in the load access and non-access states, thereby improving the detection accuracy. The diode D2 plays a role in stabilizing voltage when in high level, so that the port voltage of the resistor R1 is ensured to be high enough, and when a load is connected, the voltage of the resistor R1 is rapidly reduced through the voltage drops of the diode D1 and the diode D2, so that the sensitivity to the change of the load connection state is improved. In a further preferred embodiment, the power supply VCC provides a small voltage of 3.3V, and the resistor R10 is a large resistor of the order of kiloohms, for example, the resistance value of the resistor R10 is 150 kiloohms. It should be noted that, the resistor with high resistance can significantly reduce the power consumption of the circuit. When the resistance of the resistor R10 is 150 kilo-ohms, the current flowing through the resistor is small. Low current means low power consumption, which is particularly important in battery-powered BMS systems, helping to extend the life of the battery. In addition, the resistor R10 with high resistance can limit the current, prevent the current from being too large when the circuit is abnormal (such as short circuit or load change), and protect other elements in the circuit from damage. The high-resistance resistor can provide a stable high-level signal in a normal working state, so that the load detection circuit 102 can accurately detect the access state of the load. When a load is connected, the high resistance value of the resistor R10 enables the voltage drop to be rapid and obvious, so that the detection sensitivity is improved.
In some preferred embodiments, the analog load access switch circuit 103 includes an analog load access switch J1, a resistor RL, and a resistor R2; one end of the analog load access switch J1 is commonly connected with the cathode of the diode D1, the drain electrode of the MOS tube Q2A, the charging detection circuit 106 and the analog charger access switch circuit 104, the other end of the analog load access switch J is connected with the first end of the resistor RL, the second end of the resistor RL is connected with the first end of the resistor R2, and the second end of the resistor R2 is grounded; when the discharging control switch tube 100 and the charging control switch tube 101 are opened and the analog load access switch J1 is closed, the analog load access switch circuit 103 is turned on, and the load detection circuit 102 detects a load access signal. The analog load access switch circuit 103 includes an analog load access switch J1, a resistor RL, and a resistor R2, and when the J1 is closed, a current is grounded through the resistor RL and the resistor R2, and the analog load access switch circuit 103 is turned on. After being turned on, the load detection circuit 102 detects a load access signal and outputs the load access signal to the MCU of the BMS. In this embodiment, the analog load access switch circuit 103 is implemented by a simple switch and a resistor, so as to facilitate the access state of the analog load and improve the detection accuracy.
In some preferred embodiments, the analog charger access switch circuit 104 comprises an analog charger access switch J2 and a charging power supply Charg, wherein one end of the analog charger access switch J2 is commonly connected with the drain electrode of the MOS transistor Q2A, the charging detection circuit 106, the analog load access switch circuit 103 and the load detection circuit 102, the other end is connected with the positive electrode of the charging power supply Charg, and the negative electrode of the charging power supply Charg is grounded. It should be noted that, the analog charger access switch circuit 104 includes an analog charger access switch J2 and a charging power supply Charg, and when the analog charger access switch J2 is closed, the charging power supply is connected to the drain of the MOS transistor Q2A through the analog charger access switch J2. When the MOS transistor Q3A is disconnected and the analog charger access switch J2 is turned on, the charging power supply Charg is divided by the resistor R4 and the resistor R5 of the charging detection circuit 106, so that the triode Q1 is turned on, the resistor R6 is pulled down, and the charging detection circuit 106 outputs a charger access signal to the MCU of the BMS.
In some preferred embodiments, the charge detection circuit 106 includes a resistor R3, a resistor R4, a resistor R5, a resistor R6, a resistor R7, and a transistor Q1; the first end of the resistor R4 is commonly connected with the drain electrode of the MOS tube Q2A, the analog load access switch circuit 103, the load detection circuit 102 and the analog charger access switch circuit 104, and the second end of the resistor R4 is commonly connected with the first end of the resistor R3 and the first end of the resistor R5; the second end of the resistor R3 is connected with the base electrode of the triode Q1, and the second end of the resistor R5 is grounded; the collector of triode Q1 connects the first end of resistance R6 and the first end of resistance R7, and power VCC is connected to resistance R6's second end, and resistance R7's second end output the charger access signal of detecting gives the MCU to BMS. Wherein the level through resistor R6 defaults to a high level. The charge detection circuit 106 is implemented by a resistor R3, a resistor R4, a resistor R5, a resistor R6, a resistor R7, and a transistor Q1, and when the drain of the MOS transistor Q2A is at a high level, the resistor R4 and the resistor R5 divide the voltage to turn on the Q1, and the resistor R6 is pulled down. The level change of the resistor R6 detects an access signal of the charger and outputs to the MCU of the BMS. In this embodiment, the charging detection circuit 106 has a simple structure, is realized through a resistor and a triode, is convenient to realize and maintain, can improve the accuracy and reliability of charging detection, effectively prevents the occurrence of charging overcurrent or short circuit conditions, and improves the safety and stability of the circuit.
In a further preferred embodiment, the power supply VCC to which the resistor R6 is connected provides a small voltage of 3.3V, the resistor R6 being a large resistor of the order of kiloohms, for example, the resistance of the resistor R6 being 500 kiloohms. It should be noted that, the resistor R6 (500 kohms) with a high resistance can significantly reduce the power consumption of the circuit. According to ohm's law, when VCC is 3.3V, the current flowing through the resistor R6 is low current in microampere level, which means low power consumption, which is particularly important for battery-powered BMS systems, helping to extend the life of the battery. In addition, the resistor R6 with a high resistance can provide a stable high-level signal in a normal working state, so as to ensure that the charging detection circuit 106 can correctly detect the access state of the charger. When the charger is connected, the triode Q1 is conducted through the voltage division of the resistor R4 and the resistor R5, the level of the resistor R6 is pulled down, and obvious voltage change is generated, so that the MCU is convenient to detect a charger connection signal. Meanwhile, the high-resistance resistor R6 can limit the current passing through the triode Q1, prevent the overlarge current under abnormal conditions and protect the triode and other elements from being damaged.
In some preferred embodiments, the discharge control switch tube 100 is controlled to be turned off by the discharge control signal when overdischarged, and the charge control switch tube 101 is controlled to be turned off by the charge control signal when overcharged.
It should be noted that, the level of the resistor R10 defaults to pass through the high level, when the MOS transistor Q2A and the MOS transistor Q3A are turned off and the load access of the analog load access switch J1 is turned on, the level of the resistor R10 is pulled down by the load, so that the MCU of the BMS can detect the load access signal. The resistor R6 level defaults to pass through the high level, and when MOS pipe Q3A disconnection, just analog charger access switch J2 switches on, charging source Charg passes through resistance R4, and resistance R5 partial pressure, triode Q1 switches on, and resistance R6 is pulled down to BMS's MCU can detect the charger access signal.
It should be noted that the above embodiments are only preferred embodiments of the present invention, and the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily contemplated by those skilled in the art within the technical scope of the present invention should be covered by the scope of the present invention, which is defined by the claims.