CN219477658U - Uninterrupted power supply circuit - Google Patents

Abstract

The utility model provides a circuit for uninterrupted power supply, which comprises a first port, a second port, a third port and a fourth port; the first port and the second port are connected with an energy storage battery; the first MOS tube, the second MOS tube, the third MOS tube and the fourth MOS tube form a bidirectional DC-DC circuit; the first input end of the control chip is connected with the first port, the second input end of the control chip is connected with one end of the inductor, the other end of the inductor is connected with one end of the thermistor, and the other end of the thermistor is connected with the third interface; the positive electrode of the energy storage capacitor is connected with the second input end of the control chip, and the negative electrode of the energy storage capacitor is grounded; the drain electrode of the fifth MOS tube is connected with the fourth port, the source electrode of the fifth MOS tube is grounded, and the grid electrode of the fifth MOS tube is connected with the third port; by the technical scheme, on the premise of a direct current power supply system in the equipment disengaging station, long-time stable electric energy can be provided for the equipment disengaging station.

Description

A circuit for uninterrupted power supply

technical field

The utility model relates to the technical field of electric power system current measurement, in particular to a circuit for uninterrupted power supply.

Background technique

Relay protection (secondary equipment), as the first line of defense of the power grid, undertakes the important task of quickly removing and isolating faults, and is the "360 security guard" of the power system. The DC system in the substation is an important system that supplies power to the relay protection device, its control circuit, and the outlet circuit, and affects the correctness of the protection action. Therefore, the DC system is an important system that affects the stable operation of the power grid. In general, problems in the DC system will directly affect the stability and security of the overall operation of the power grid.

The DC system is an important power supply system for the control circuit, relay protection device and its outlet circuit of the substation. In large and medium-sized substations, the DC system is used as the "aorta and capillaries" in the substation and spreads all over the station. However, when an abnormal problem occurs in the DC system in the station, on-site maintenance personnel often need to disconnect the corresponding DC switches one by one to find the exact fault point, which will cause some normally operating DC feeders to be forced to power outage during the process of finding the fault point. As a result, short-term power outages occurred in relevant important secondary equipment, which seriously affected the safe and stable operation of the power system.

Utility model content

In view of this, the purpose of this utility model is to provide a circuit for uninterrupted power supply, which can provide stable electric energy for a long time on the premise that the equipment is separated from the DC power supply system in the station.

In order to achieve the above purpose, the utility model adopts the following technical solutions: a circuit for uninterrupted power supply, including a first port, a second port, a third port and a fourth port; the first port and the second port are connected to the energy storage The battery; also includes a control chip, an inductor, a thermistor, an energy storage capacitor, a first MOS tube, a second MOS tube, a third MOS tube, a fourth MOS tube, and a fifth MOS tube; the first MOS tube, the second MOS tube The two MOS transistors, the third MOS transistor and the fourth MOS transistor form a bidirectional DC-DC circuit; the first input end of the control chip is connected to the first port, the second input end of the control chip is connected to one end of the inductor, and the The other end of the inductor is connected to one end of the thermistor, and the other end of the thermistor is connected to the third port; the positive pole of the energy storage capacitor is connected to the second input end of the control chip, and the anode of the energy storage capacitor is connected to the second input terminal of the control chip. The negative pole is grounded; the drain of the fifth MOS transistor is connected to the fourth port, the source of the fifth MOS transistor is grounded, and the gate of the fifth MOS transistor is connected to the third port.

In a preferred embodiment, the gate of the first MOS transistor is connected to one end of the first resistor, the other end of the first resistor is connected to the cathode of the first diode, and the anode of the first diode is connected to the second One end of the resistor, the other end of the second resistor is connected to one end of the third resistor, one end of the third resistor is grounded, and the source of the first MOS transistor is grounded.

In a preferred embodiment, the gate of the second MOS transistor is connected to one end of the fourth resistor, and the other end of the fourth resistor is connected to the cathode of the second diode. The anode is connected to one end of the fifth resistor, the other end of the fifth resistor is connected to one end of the sixth resistor, the other end of the sixth resistor is grounded, and the source of the second MOS transistor is grounded.

In a preferred embodiment, the gate of the third MOS transistor is connected to one end of the seventh resistor, one end of the eighth resistor, and one end of the ninth resistor, and the other end of the seventh resistor and the third MOS transistor The source of the eighth resistor is connected to the drain of the first MOS transistor; the other end of the eighth resistor is connected to the cathode of the third diode, and the other end of the ninth resistor is connected to the anode of the third diode; The drain of the third MOS transistor is connected to one end of the thermistor.

In a preferred embodiment, the gate of the fourth MOS transistor is connected to one end of the tenth resistor, one end of the eleventh resistor, and one end of the twelfth resistor; the other end of the tenth resistor and the fourth The source of the MOS transistor is connected to the drain of the first MOS transistor, the other end of the eleventh resistor is connected to the cathode of the fourth diode, and the other end of the twelfth resistor is connected to the fourth diode. positive electrode; the drain of the fourth MOS tube is connected to one end of the thermistor.

In a preferred embodiment, in the normal charging mode, the third port and the fourth port are connected to the DC power supply in the station; the fifth MOS transistor makes the loop conduction, and the electric energy provided by the DC in the station passes through the thermistor, and a part Charge the high-density energy storage electric energy, and the other part charges the lithium battery pack connected to the first port and the second port through a bidirectional DC-DC circuit.

In a preferred embodiment, when charging is in reverse connection mode, that is, the positive and negative poles of the third port and the fourth port are reversed, the fifth MOS transistor is in the reverse cut-off state and cannot be turned on, and the circuit is disconnected from the DC power supply in the station. Open the connection.

In a preferred embodiment, in the short-term power supply mode, the third port and the fourth port are connected to the load in the station. When the DC power supply is lost in the station, the energy storage capacitor provides power for the DC load in the station through the fifth MOS tube. .

In a preferred embodiment, in the long-term power supply mode, the third port and the fourth port are connected to the load in the station, and the energy storage capacitor provides power for the DC load in the station through the fifth MOS transistor. When the voltage of the energy storage capacitor drops to the set When the threshold is set, the electric energy in the lithium battery pack on the third port and the fourth port supplies power to the energy storage capacitor and the DC load in the station through a bidirectional DC-DC circuit.

Compared with the prior art, the utility model has the following beneficial effects: on the premise that the equipment is separated from the DC power supply system in the station, it can provide stable electric energy for a long time.

Description of drawings

Fig. 1 is the main circuit diagram of the uninterrupted power supply of the preferred embodiment of the utility model;

Fig. 2 is a schematic diagram of a human-computer interaction circuit in a preferred embodiment of the present invention for driving a corresponding indicator light circuit;

Fig. 3 is a series of operational amplifier circuits of the preferred embodiment of the present invention.

Detailed ways

Below in conjunction with accompanying drawing and embodiment the utility model is described further.

It should be pointed out that the following detailed description is exemplary and intended to provide further explanation to the present application. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

It should be noted that the terms used here are only for describing specific embodiments, and are not intended to limit exemplary embodiments according to the present application; as used herein, unless the context clearly indicates otherwise, the singular form is also intended to include In addition, it should also be understood that when the terms "comprising" and/or "comprising" are used in this specification, it indicates the presence of features, steps, operations, means, components and/or combinations thereof.

An uninterruptible power supply circuit, referring to Figure 1, includes a first port P1, a second port P2, a third port P3, and a fourth port P4; the first port P1 and the second port P2 are connected to an energy storage battery; Including control chip, inductor, thermistor NTC1, energy storage capacitor, first MOS transistor Q1, second MOS transistor Q2, third MOS transistor Q3, fourth MOS transistor Q4 and fifth MOS transistor Q5; the first MOS transistor The tube Q1, the second MOS tube Q2, the third MOS tube Q3 and the fourth MOS tube Q4 form a bidirectional DC-DC circuit; the first input end IP- of the control chip is connected to the first port, and the second MOS tube of the control chip The input terminal IP+ is connected to one end of the inductance, the other end of the inductance is connected to one end of the thermistor NTC1, and the other end of the thermistor NTC1 is connected to the third port P3; the positive pole of the energy storage capacitor is connected to the control The second input end of the chip, a diode is connected between the anode of the energy storage capacitor and the second input end of the control chip; the negative electrode of the energy storage capacitor is grounded; the drain of the fifth MOS transistor Q5 is connected to the fourth Port P4, the source of the fifth MOS transistor Q5 is grounded, and the gate of the fifth MOS transistor Q5 is connected to the third port P3.

The gate of the first MOS transistor Q1 is connected to one end of the first resistor R9, the other end of the first resistor R9 is connected to the cathode of the first diode D1, and the anode of the first diode D1 is connected to one end of the second resistor R5 , the other end of the second resistor R5 is connected to one end of the third resistor R1, one end of the third resistor R1 is grounded, and the source of the first MOS transistor Q1 is grounded.

The gate of the second MOS transistor Q2 is connected to one end of the fourth resistor R10, the other end of the fourth resistor R10 is connected to the cathode of the second diode D2, and the anode of the second diode D2 is connected to the fifth One end of the resistor R6, the other end of the fifth resistor R6 is connected to one end of the sixth resistor R2, the other end of the sixth resistor R2 is grounded, and the source of the second MOS transistor Q2 is grounded.

The gate of the third MOS transistor Q3 is connected to one end of the seventh resistor R3, one end of the eighth resistor R7, and one end of the ninth resistor R11, and the other end of the seventh resistor R3 is connected to the source of the third MOS transistor Q3 connected to the drain of the first MOS transistor Q1; the other end of the eighth resistor R7 is connected to the cathode of the third diode D4, and the other end of the ninth resistor R11 is connected to the third diode D4 positive electrode; the drain of the third MOS transistor Q3 is connected to one end of the thermistor NTC1.

The gate of the fourth MOS transistor Q4 is connected to one end of the tenth resistor R12, one end of the eleventh resistor R8, and one end of the twelfth resistor R4; the other end of the tenth resistor R12 and the fourth MOS transistor Q4 The source is connected to the drain of the first MOS transistor Q1, the other end of the eleventh resistor R8 is connected to the cathode of the fourth diode D3, and the other end of the twelfth resistor R4 is connected to the fourth diode The anode of D3; the drain of the fourth MOS transistor Q4 is connected to one end of the thermistor NTC1.

There are four working modes in total, which are normal charging mode, reverse charging mode, short-time power supply mode and long-time power supply mode. The above four modes correspond to the following four situations:

① When the device is working in the normal charging mode, the circuit turns on the circuit through the fifth MOS switch Q5. After the electric energy provided by the DC in the station passes through the thermistor NTC1, part of it charges the high-density energy storage electric energy, and the other part passes through the first The bidirectional DC-DC circuit composed of MOS transistor Q1, second MOS transistor Q2, third MOS transistor Q3 and fourth MOS transistor Q4 charges the lithium battery pack connected to the first port P1 and the second port P2, wherein the thermistor NTC1 is designed to limit the short-circuit current when the subsequent circuit fails.

②When the device is in reverse charging mode, that is, the positive and negative poles of the third port P3 and the fourth port P4 are reversed. At this time, the fifth MOS transistor Q5 is in a reverse cut-off state and cannot be turned on, and the circuit is disconnected from the DC power supply in the station. This design not only protects the safety of the DC system in the station, but also protects the personal safety of the equipment users.

③When the equipment works in the short-term power supply mode, when the DC power supply is lost in the station, the energy storage capacitor can provide power for the DC load in the station through the fifth MOS transistor Q5, and due to the characteristics of the energy storage capacitor, it is in the power supply mode Stepless switching between charging and charging modes.

④ When the equipment works in the long-term power supply mode, the energy storage capacitor provides power for the DC load in the station through the fifth MOS transistor Q5. When the voltage of the energy storage capacitor drops to the set threshold, the third port P3 and the fourth port P4 The electric energy in the lithium battery pack supplies power to the energy storage capacitor and the DC load in the station through the bidirectional DC-DC circuit composed of the first MOS transistor Q1, the second MOS transistor Q2, the third MOS transistor Q3 and the fourth MOS transistor Q4. At this time, the energy storage capacitor also plays a role in suppressing the starting voltage pulse.

The first port P1 and the second port P2 of the uninterruptible power supply circuit for the substation are connected to the energy storage lithium battery pack to provide stable power for the equipment in the substation for a long time. When the device is working in the charging mode, the third port P3 and the fourth port P4 are connected to the DC power supply in the station to complete the charging of the device; when the device is working in the power supply mode, the third port P3 and the fourth port P4 are connected to the corresponding load.

This circuit is mainly used by on-site maintenance personnel in the process of finding DC faults in substations. Therefore, this patent designs a human-computer interaction circuit as shown in Figure 2 to drive the corresponding indicator lights and reflect the working status of the circuit, so as to make better use of this circuit. circuit to work.

Since the circuit is an uninterrupted power supply circuit in the substation, and the equipment in the substation is all important equipment, which has high requirements on the quality of power supply, and most of them are powered by 220V DC, so there are more stringent requirements on the stability of power supply for this circuit. Therefore, a series of operational amplifier circuits as shown in Figure 3 are designed and used to realize the function of providing a stable 220V DC power supply.

Claims (9)

1. A circuit for uninterrupted power supply, characterized in that it includes a first port, a second port, a third port and a fourth port; the first port and the second port are connected to an energy storage battery; also includes a control chip, an inductor , a thermistor, an energy storage capacitor, a first MOS tube, a second MOS tube, a third MOS tube, a fourth MOS tube, and a fifth MOS tube; the first MOS tube, the second MOS tube, and the third MOS tube and the fourth MOS transistor to form a bidirectional DC-DC circuit; the first input end of the control chip is connected to the first port, the second input end of the control chip is connected to one end of the inductor, and the other end of the inductor is connected to the heat One end of the sensitive resistor, the other end of the thermistor is connected to the third port; the positive pole of the energy storage capacitor is connected to the second input terminal of the control chip, and the negative pole of the energy storage capacitor is grounded; the fifth MOS The drain of the transistor is connected to the fourth port, the source of the fifth MOS transistor is grounded, and the gate of the fifth MOS transistor is connected to the third port. 2. The uninterruptible power supply circuit according to claim 1, wherein the gate of the first MOS transistor is connected to one end of the first resistor, and the other end of the first resistor is connected to the cathode of the first diode, The anode of the first diode is connected to one end of the second resistor, the other end of the second resistor is connected to one end of the third resistor, one end of the third resistor is grounded, and the source of the first MOS transistor is grounded. 3. The uninterruptible power supply circuit according to claim 2, wherein the gate of the second MOS transistor is connected to one end of the fourth resistor, and the other end of the fourth resistor is connected to the second diode. Negative electrode, the anode of the second diode is connected to one end of the fifth resistor, the other end of the fifth resistor is connected to one end of the sixth resistor, the other end of the sixth resistor is grounded, and the second MOS transistor Source ground. 4. The uninterruptible power supply circuit according to claim 3, wherein the gate of the third MOS transistor is connected to one end of the seventh resistor, one end of the eighth resistor, and one end of the ninth resistor, and the first The other end of the seven resistors and the source of the third MOS transistor are connected to the drain of the first MOS transistor; the other end of the eighth resistor is connected to the cathode of the third diode, and the other end of the ninth resistor is connected to The anode of the third diode; the drain of the third MOS tube is connected to one end of the thermistor. 5. The uninterruptible power supply circuit according to claim 4, wherein the gate of the fourth MOS transistor is connected to one end of the tenth resistor, one end of the eleventh resistor, and one end of the twelfth resistor; The other end of the tenth resistor and the source of the fourth MOS transistor are connected to the drain of the first MOS transistor, the other end of the eleventh resistor is connected to the cathode of the fourth diode, and the twelfth resistor The other end of the transistor is connected to the anode of the fourth diode; the drain of the fourth MOS transistor is connected to one end of the thermistor. 6. The circuit for uninterrupted power supply according to claim 5, characterized in that, in the normal charging mode, the third port and the fourth port are connected to the DC power supply in the station; After passing through the thermistor, part of the electric energy charges the high-density energy storage electric energy, and the other part charges the lithium battery pack connected to the first port and the second port through a bidirectional DC-DC circuit. 7. The circuit for uninterrupted power supply according to claim 5, characterized in that, when charging is in reverse connection mode, that is, the positive and negative poles of the third port and the fourth port are reversed, the fifth MOS transistor is in the reverse cut-off state and cannot On, the circuit is disconnected from the DC power supply in the station. 8. The circuit for uninterrupted power supply according to claim 5, characterized in that, in the short-time power supply mode, the third port and the fourth port are connected to the load in the station, and when the DC power supply is lost in the station, the energy storage capacitor passes through The fifth MOS tube provides power for the DC load in the station. 9. The circuit for uninterrupted power supply according to claim 5, characterized in that, in the long-term power supply mode, the third port and the fourth port are connected to the load in the station, and the energy storage capacitor provides the DC load in the station through the fifth MOS tube. Power supply, when the voltage of the energy storage capacitor drops to the set threshold, the electric energy in the lithium battery pack on the third port and the fourth port supplies power to the energy storage capacitor and the DC load in the station through a bidirectional DC-DC circuit.