CN113419167A - A contactor adhesion detection circuit - Google Patents

Abstract

The invention discloses an adhesion detection circuit of an energy storage battery cluster contactor, which comprises a battery cluster, a Hall sensor, a main contactor, a pre-charging contactor, a current-limiting resistor, a first adhesion detection control optocoupler, a first adhesion detection optocoupler, a second adhesion detection control optocoupler, a second adhesion detection optocoupler, a bidirectional energy storage converter, a battery management system and a low voltage source.

Description

Contactor adhesion detection circuitry

Technical Field

The invention relates to a detection circuit, in particular to a contactor adhesion detection circuit.

Background

The current energy storage system is composed of a plurality of battery clusters, a main contactor and a pre-charging contactor are configured in a single battery cluster, after the system is powered on, the pre-charging contactor is closed firstly after the battery management system detects that the battery cluster is abnormal, and when the voltages at the two ends of the pre-charging contactor reach a certain difference value, the main contactor is closed so as to achieve the purpose of protecting the main contactor from being impacted by large current.

Through the precharge, behind the closed main contactor of system, can get into normal charge-discharge operating condition, along with factors such as the long-time operation of system and device are ageing, the battery is restrainted in the charge-discharge process, the contactor contact can be because long-time area carries the operation to generate heat and the contact adhesion condition appears, this just needs battery management system to detect whether the adhesion of contactor contact to guarantee that the system in time points out when unusual, in time intervenes, avoids the battery to crowd because the unable overcharge or the overdischarge that the disconnection caused of contactor contact adhesion.

As shown in fig. 2, in the prior art, when a battery management system is powered on, the battery management system performs contactor adhesion state detection, both contactors are in an off state, the battery management system preferentially detects a voltage at a voltage detection point 1, and since the voltage detection point 1 is a positive electrode of a battery cluster and reflects the voltage as a total voltage of the battery cluster, a detection value corresponding to the voltage of the battery cluster always exists;

after the battery management system detects voltage of a voltage detection point 1, voltage of avoltage detection point 2 is carried out subsequently, so that the battery management system is closed by the two control contactors, the two contactors are in an off state, thevoltage detection point 2 is in a voltage-free state, if the battery management system detects that the voltage of thevoltage detection point 2 and the voltage detection point 1 tend to be consistent, the contactors are judged to be adhered, and corresponding alarm is carried out.

However, the prior art has the following disadvantages:

in the prior art, under the condition that a battery management system does not control the closing of contactors, the voltages of a voltage detection point 1 and avoltage detection point 2 are compared, whether the contactors are adhered or not is judged through software, when any one of the two contactors is adhered, the voltage value close to the voltage detection point 1 at thevoltage detection point 2 is difficult to position whether a pre-charging contactor is adhered or a main contactor is adhered, the reliability is low, and faults are difficult to effectively prompt;

when the battery system has more frequent charge and discharge switching or power-on and power-off operation, if residual voltage exists at the PCS side at the moment, a certain voltage value exists at thevoltage detection 2 point, a larger detection error may occur, and a false alarm fault may occur;

however, the solution requires that the battery system be very strictly matched with the PCS or the discharge timing sequence, which increases the logic complexity and reduces the safety.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provides a contactor adhesion detection circuit which is high in detection accuracy, low in logic complexity and high in safety.

In order to achieve the aim, the contactor adhesion detection circuit comprises a battery cluster, a Hall sensor, a main contactor, a pre-charging contactor, a current-limiting resistor, a first adhesion detection control optocoupler, a first adhesion detection optocoupler, a second adhesion detection control optocoupler, a second adhesion detection optocoupler, a bidirectional energy storage converter, a battery management system and a low-voltage power supply;

the positive pole of the battery cluster is connected with one end of a main contactor through a Hall sensor, a pin No. 4 of a first adhesion detection control optocoupler and one end of a current limiting resistor are connected, the other end of the current limiting resistor is connected with one end of a pre-charging contactor and a pin No. 4 of a second adhesion detection control optocoupler, the other end of the main contactor, the other end of the pre-charging contactor, a pin No. 2 of a first adhesion detection optocoupler, a pin No. 2 of a second adhesion detection optocoupler and the positive pole of the direct current side in a bidirectional energy storage converter are connected, the negative pole of the direct current side in the bidirectional energy storage converter is connected with the negative pole of the battery cluster, a pin No. 3 of the first adhesion detection control optocoupler is connected with a pin No. 1 of the first adhesion detection optocoupler through a first resistor, and a pin No. 3 of the second adhesion detection optocoupler is connected with a pin No. 1 of the second adhesion detection optocoupler through a second resistor;

the battery management system is connected with the Hall sensor, a No. 2 pin of the first adhesion detection control optocoupler, a No. 2 pin of the second adhesion detection control optocoupler, a No. 4 pin of the first adhesion detection optocoupler, a No. 4 pin of the second adhesion detection optocoupler, a control end of the main contactor and a control end of the pre-charging contactor;

the No. 1 pin of the first adhesion detection control optocoupler is connected with a low-voltage source through a third resistor; the No. 4 pin of the first adhesion detection optocoupler is connected with a low voltage source through a fourth resistor, the No. 1 pin of the second adhesion detection control optocoupler is connected with the low voltage source through a fifth resistor, and the No. 4 pin of the second adhesion detection optocoupler is connected with the low voltage source through a sixth resistor;

no. 3 pin of first adhesion detection opto-coupler and No. 3 pin of second adhesion detection opto-coupler all ground connection.

When the battery management system works, after the battery management system is powered on, the main contactor and the pre-charging contactor are in an off state at the moment, the battery management system controls the conduction of the No. 3 pin and the No. 4 pin of the first adhesion detection control optocoupler, when the main contactor is adhered at the moment, the total voltage and current of a battery cluster are directly connected to the load side through the contact of the main contactor, the No. 3 pin and the No. 4 pin of the first adhesion detection control optocoupler and the No. 1 pin and the No. 2 pin of the first adhesion detection optocoupler have no current flowing through, the No. 3 pin and the No. 4 pin of the first adhesion detection optocoupler are in a non-conduction state, the No. 4 pin of the second adhesion detection optocoupler is at a high level, and the battery management system judges that the main contactor is adhered and sends out a corresponding alarm;

when the battery management system is in work, after the battery management system is powered on, the main contactor and the pre-charging contactor are in an off state at the moment, the battery management system controls the connection of the pin 3 and the pin 4 of the first adhesion detection control optocoupler, when the main contactor is not adhered at the moment, the total voltage and current of the battery cluster are connected to the load side through the pin 3 of the first adhesion detection control optocoupler, the pin 4 and the pin 1 and thepin 2 of the first adhesion detection optocoupler, the pin 3 and the pin 4 of the first adhesion detection optocoupler are in an on state, the pin 4 of the first adhesion detection optocoupler is at a low level, and the battery management system judges that the contact of the main contactor is normally in a non-adhesion state;

when the battery management system is powered on, the main contactor and the pre-charging contactor are in an off state at the moment, the battery management system controls the conduction of a pin 3 and a pin 4 of the second adhesion detection control optocoupler, when the pre-charging contactor is adhered at the moment, the total voltage and current of a battery cluster are directly connected to the load side through a contact of the pre-charging contactor, the pin 3 and the pin 4 of the second adhesion detection control optocoupler and a pin 1 and apin 2 of the second adhesion detection optocoupler have no current flowing through, the pin 3 and the pin 4 of the second adhesion detection optocoupler are in a non-conduction state, the pin 4 of the second adhesion detection optocoupler is at a high level, the battery management system judges that the pre-charging contactor is adhered, and sends out a corresponding alarm signal;

when the battery management system works, after the battery management system is powered on, the main contactor and the pre-charging contactor are in an off state, the battery management system controls the connection of the No. 3 pin and the No. 4 pin of the second adhesion detection control optocoupler, when the main contactor is not adhered at the moment, the total voltage and current of the battery cluster are connected to the load side through the No. 3 pin and the No. 4 pin of the second adhesion detection control optocoupler and the No. 1 pin and the No. 2 pin of the second adhesion detection optocoupler, the No. 3 pin and the No. 4 pin of the second adhesion detection optocoupler are in an on state, the No. 4 pin of the second adhesion detection optocoupler is at a low level, and the battery management system judges that the contact of the pre-charging contactor is normally in a non-adhesion state;

when the battery management system detects that the main contactor and the pre-charging contactor are in a non-adhesion state during operation, the main contactor and the pre-charging contactor are closed, and the battery cluster is charged and discharged; otherwise, carrying out alarm prompt and prohibiting charging and discharging of the system.

The invention has the following beneficial effects:

when the contactor adhesion detection circuit is specifically operated, the adhesion states of the two contactors can be judged by controlling the switch states of the main contactor and the pre-charging contactor and detecting the voltage levels of the pin 4 in the optical coupler and the pin 4 in the second adhesion detection optical coupler according to the first adhesion, and the current adhesion is pre-charging contactor adhesion or main contactor adhesion so as to effectively locate a fault point.

Drawings

FIG. 1 is a schematic structural view of the present invention;

fig. 2 is a schematic structural diagram of the prior art.

Detailed Description

In order to make the technical solutions of the present invention better understood, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, not all of the embodiments, and are not intended to limit the scope of the present disclosure. Moreover, in the following description, descriptions of well-known structures and techniques are omitted so as to not unnecessarily obscure the concepts of the present disclosure. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

There is shown in the drawings a schematic block diagram of a disclosed embodiment in accordance with the invention. The figures are not drawn to scale, wherein certain details are exaggerated and possibly omitted for clarity of presentation. The shapes of various regions, layers and their relative sizes and positional relationships shown in the drawings are merely exemplary, and deviations may occur in practice due to manufacturing tolerances or technical limitations, and a person skilled in the art may additionally design regions/layers having different shapes, sizes, relative positions, according to actual needs.

Referring to fig. 1, the contactor adhesion detection circuit provided by the invention comprises a battery cluster D, a hall sensor H1, a main contactor K1, a pre-charging contactor K2, a current-limiting resistor R1, a first adhesion detection control optocoupler U1, a first adhesion detection optocoupler U2, a second adhesion detection control optocoupler U3, a second adhesion detection optocoupler U4, a bidirectional energy storage converter PCS, a battery management system BMU and a low-voltage source VCC;

the positive pole of the battery cluster D is connected with one end of a main contactor K1, a pin No. 4 of a first adhesion detection control optocoupler U1 and one end of a current-limiting resistor R1 through a Hall sensor H1, the other end of the current-limiting resistor R1 is connected with one end of a pre-charging contactor K2 and a pin No. 4 of a second adhesion detection control optocoupler U3, the other end of the main contactor K1 and the other end of the pre-charging contactor K2, a pin No. 2 of the first adhesion detection optocoupler U2, a pin No. 2 of the second adhesion detection optocoupler U4 and the positive electrode of the direct current side in the bidirectional energy storage converter PCS are connected, the negative electrode of the direct current side in the bidirectional energy storage converter PCS is connected with the negative electrode of the battery cluster D, a pin No. 3 of the first adhesion detection control optocoupler U1 is connected with a pin No. 1 of the first adhesion detection optocoupler U2 through a first resistor, and a pin No. 3 of the second adhesion detection control optocoupler U3 is connected with a pin No. 1 of the second adhesion detection optocoupler U4 through a second resistor;

the battery management system BMU is connected with a Hall sensor H1, a pin No. 2 of a first adhesion detection control optocoupler U1, a pin No. 2 of a second adhesion detection control optocoupler U3, a pin No. 4 of a first adhesion detection optocoupler U2, a pin No. 4 of a second adhesion detection optocoupler U4, a control end of a main contactor K1 and a control end of a pre-charging contactor K2;

a pin No. 1 of the first adhesion detection control optocoupler U1 is connected with a low-voltage source VCC through a third resistor; no. 4 pin of first adhesion detection opto-coupler U2 is connected with low voltage source VCC through the fourth resistance, and No. 1 pin of second adhesion detection control opto-coupler U3 is connected with low voltage source VCC through the fifth resistance, and No. 4 pin of second adhesion detection opto-coupler U4 is connected with low voltage source VCC through the sixth resistance.

No. 3 pin of first adhesion detection opto-coupler U2 and No. 3 pin of second adhesion detection opto-coupler U4 all ground.

The working process of the invention is as follows:

1) adhesion detection of main contactor K1

After a battery management system BMU is powered on, the main contactor K1 and the pre-charging contactor K2 are in an off state at the moment, the battery management system BMU controls a pin 3 and a pin 4 of a first adhesion detection control optocoupler U1 to be conducted, when the main contactor K1 is adhered at the moment, the total voltage and the current of a battery cluster D are directly connected to a load side through a contact of the main contactor K1, the pin 3 and the pin 4 of a first adhesion detection control optocoupler U1 and the pin 1 and thepin 2 of a first adhesion detection optocoupler U2 do not have current to flow, the pin 3 and the pin 4 of the first adhesion detection optocoupler U2 are in a non-conducting state, the pin 4 of a second adhesion detection optocoupler U4 is at a high level, and the battery management system BMU judges that the main contactor K1 is adhered and sends out a corresponding alarm;

after a battery management system BMU is powered on, the main contactor K1 and the pre-charging contactor K2 are in an off state at the moment, the battery management system BMU controls a pin 3 and a pin 4 of a first adhesion detection control optocoupler U1 to be conducted, when the main contactor K1 is not adhered at the moment, the total voltage and current of a battery cluster D are connected to a load side through the pin 3 and the pin 4 of the first adhesion detection control optocoupler U1 and the pin 1 and thepin 2 of the first adhesion detection optocoupler U2, the pin 3 and the pin 4 of the first adhesion detection optocoupler U2 are in an on state, the pin 4 of the first adhesion detection optocoupler U2 is at a low level, and the battery management system BMU judges that a contact of the main contactor K1 is normally in an non-adhesion state;

2) pre-charge contactor K2 adhesion detection

After a battery management system BMU is powered on, the main contactor K1 and the pre-charging contactor K2 are in an off state at the moment, the battery management system BMU controls the conduction of a pin 3 and a pin 4 of a second adhesion detection control optocoupler U3, when the pre-charging contactor K2 is adhered at the moment, the total voltage and current of a battery cluster D are directly connected to the load side through a contact of the pre-charging contactor K2, the pin 3 and the pin 4 of a second adhesion detection control optocoupler U3 and the pin 1 and thepin 2 of a second adhesion detection optocoupler U4 have no current flowing, the pin 3 and the pin 4 of the second adhesion detection optocoupler U4 are in a non-conducting state, the pin 4 of the second adhesion detection optocoupler U4 is at a high level, and the battery management system BMU judges that the pre-charging contactor K2 is adhered and sends out a corresponding alarm signal;

after a battery management system BMU is powered on, a main contactor K1 and a pre-charging contactor K2 are in an off state, the battery management system BMU controls a pin 3 and a pin 4 of a second adhesion detection control optocoupler U3 to be conducted, when the main contactor K1 is not adhered at the moment, the total voltage and the current of a battery cluster D are connected to a load side through the pin 3 and the pin 4 of the second adhesion detection control optocoupler U3 and the pin 1 and thepin 2 of a second adhesion detection optocoupler U4, the pin 3 and the pin 4 of the second adhesion detection optocoupler U4 are in an on state, the pin 4 of the second adhesion detection optocoupler U4 is at a low level, and the battery management system BMU judges that a contact of the pre-charging contactor K2 is normally in an non-adhesion state;

3) when the BMU detects that the main contactor K1 and the pre-charging contactor K2 are in a non-adhesion state, the main contactor K1 and the pre-charging contactor K2 are closed, and the battery cluster D performs charging and discharging operations; otherwise, alarming and prompting the PCS and prohibiting charging and discharging of the system.

It should be noted that the on-off states of the main contactor K1 and the pre-charging contactor K2 are controlled, the voltage levels of the pin 4 in the first adhesion detection optocoupler U2 and the pin 4 in the second adhesion detection optocoupler U4 are detected, the adhesion states of the two contactors can be judged, and whether the current adhesion is the adhesion of the pre-charging contactor or the adhesion of the main contactor is distinguished, so that the operation is convenient and simple, and the practicability is strong.

Claims (6)

1. A contactor adhesion detection circuit is characterized by comprising a battery cluster (D), a Hall sensor (H1), a main contactor (K1), a pre-charging contactor (K2), a current-limiting resistor (R1), a first adhesion detection control optocoupler (U1), a first adhesion detection optocoupler (U2), a second adhesion detection control optocoupler (U3), a second adhesion detection optocoupler (U4), a bidirectional energy storage converter (PCS), a battery management system (BMU) and a low-voltage source (VCC);

the positive pole of the battery cluster (D) is connected with one end of a main contactor (K1), a pin 4 of a first adhesion detection control optocoupler (U1) and one end of a current-limiting resistor (R1) through a Hall sensor (H1), the other end of the current-limiting resistor (R1) is connected with one end of a pre-charging contactor (K2) and a pin 4 of a second adhesion detection control optocoupler (U3), the other end of the main contactor (K1), the other end of the pre-charging contactor (K2), a pin 2 of a first adhesion detection optocoupler (U2), a pin 2 of the second adhesion detection optocoupler (U4) and the positive pole of the direct current side in a bidirectional energy storage converter (PCS) are connected, the negative pole of the direct current side in the bidirectional energy storage converter (PCS) is connected with the negative pole of the battery cluster (D), a pin 3 of the first adhesion detection control optocoupler (U1) is connected with a pin 1 of the first adhesion detection optocoupler (U2) through a first resistor, the No. 3 pin of the second adhesion detection control optocoupler (U3) is connected with the No. 1 pin of the second adhesion detection optocoupler (U4) through a second resistor;

the battery management system (BMU) is connected with the Hall sensor (H1), a No. 2 pin of the first adhesion detection control optocoupler (U1), a No. 2 pin of the second adhesion detection control optocoupler (U3), a No. 4 pin of the first adhesion detection optocoupler (U2), a No. 4 pin of the second adhesion detection optocoupler (U4), a control end of the main contactor (K1) and a control end of the pre-charging contactor (K2);

a No. 1 pin of the first adhesion detection control optocoupler (U1) is connected with a low voltage source (VCC) through a third resistor; a No. 4 pin of the first adhesion detection optocoupler (U2) is connected with a low voltage source (VCC) through a fourth resistor, a No. 1 pin of the second adhesion detection control optocoupler (U3) is connected with the low voltage source (VCC) through a fifth resistor, and a No. 4 pin of the second adhesion detection optocoupler (U4) is connected with the low voltage source (VCC) through a sixth resistor;

no. 3 pin of first adhesion detection opto-coupler (U2) and No. 3 pin of second adhesion detection opto-coupler (U4) all ground.

2. The contactor adhesion detection circuit according to claim 1, wherein in operation, after the battery management system (BMU) is powered on, the main contactor (K1) and the pre-charging contactor (K2) are in an off state, the battery management system (BMU) controls the pin 3 and the pin 4 of the first adhesion detection control optocoupler (U1) to be in a conducting state, when the main contactor (K1) is adhered, the total voltage and current of the battery cluster (D) are directly connected to the load side through the contact of the main contactor (K1), the pin 3 and the pin 4 of the first adhesion detection control optocoupler (U1) and the pin 1 and the pin 2 of the first adhesion detection optocoupler (U2) have no current flowing, the pin 3 and the pin 4 of the first adhesion detection optocoupler (U2) are in a non-conducting state, the pin 4 of the second adhesion detection optocoupler (U4) is at a high level, and the battery management system (BMU) judges that the main contactor (K1) is adhered and sends out a corresponding alarm.

3. The contactor stick detection circuit of claim 1, wherein, in operation, after a battery management system (BMU) is electrified, the main contactor (K1) and the pre-charging contactor (K2) are in an off state at the moment, the battery management system (BMU) controls the conduction of a No. 3 pin and a No. 4 pin of a first adhesion detection control optocoupler (U1), and when the main contactor (K1) is not adhered, then the total voltage and the electric current of battery cluster (D) detect No. 3 pin of control opto-coupler (U1) through first adhesion, No. 4 pin and No. 1 pin of first adhesion detection opto-coupler (U2), No. 2 pin is connected to the load side, No. 3 pin of first adhesion detection opto-coupler (U2), No. 4 pin is in the on-state, No. 4 pin department of first adhesion detection opto-coupler (U2) is the low level, battery management system (BMU) judge that the contact of main contactor (K1) normally is the non-adhesion state.

4. The contactor adhesion detection circuit according to claim 1, wherein in operation, after the battery management system (BMU) is powered on, the main contactor (K1) and the pre-charging contactor (K2) are in an off state, the battery management system (BMU) controls the pin 3 and the pin 4 of the second adhesion detection control optocoupler (U3) to be in conduction, when the pre-charging contactor (K2) is adhered, the total voltage and current of the battery cluster (D) are directly connected to the load side through the contact of the pre-charging contactor (K2), the pin 3 and the pin 4 of the second adhesion detection optocoupler (U3) and the pin 1 and the pin 2 of the second adhesion detection optocoupler (U4) have no current flowing, the pin 3 and the pin 4 of the second adhesion detection optocoupler (U4) are in a non-conduction state, the pin 4 of the second adhesion detection optocoupler (U4) is at a high level, and the battery management system (BMU) judges that the pre-charging contactor (K2) is adhered, and sends out corresponding alarm signals.

5. The contactor stick detection circuit of claim 1, wherein, in operation, after a battery management system (BMU) is electrified, a main contactor (K1) and a pre-charging contactor (K2) are in an off state, the battery management system (BMU) controls a No. 3 pin and a No. 4 pin of a second adhesion detection control optocoupler (U3) to be conducted, when the main contactor (K1) is not adhered, then the total voltage and the electric current of battery cluster (D) detect No. 3 pin and No. 4 pin of control opto-coupler (U3) and No. 1 pin and No. 2 pin of opto-coupler (U4) and second adhesion through the second adhesion and be connected to the load side, No. 3 pin of opto-coupler (U4) is detected to the second adhesion, No. 4 pin is in the on-state, No. 4 pin of opto-coupler (U4) is detected to the second adhesion is low level, battery management system (BMU) judges that the contact of pre-charging contactor (K2) normally is the non-adhesion state.

6. The contactor sticking detection circuit according to claim 1, wherein, in operation, when the battery management system (BMU) detects that the main contactor (K1) and the pre-charging contactor (K2) are both in a non-sticking state, the main contactor (K1) and the pre-charging contactor (K2) are closed, and the battery cluster (D) is charged and discharged; otherwise, carrying out alarm prompt and prohibiting charging and discharging of the system.

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