Direct current distribution current protection circuit

Abstract

The utility model discloses a DC power distribution current protection circuit, and belongs to the technical field of DC power distribution. Comprising at least two groups of commutator circuits, the input ends of the commutator circuits are connected with the output end of a generator, the output ends of the commutator circuits are respectively connected with the input end of an inversion sub-circuit and the input end of a voltage reduction and transformation sub-circuit, and the output end of the inversion sub-circuit is connected with alternating-current load equipment to supply power to alternating-current equipment. The rectification sub-circuit comprises a voltage stabilizing unit, the input end of the voltage stabilizing unit is connected with the output end of a generator, one output end of the voltage stabilizing unit is connected with one end of a relay J1, the other end of the relay J1 is connected with the positive electrode of a diode D30, and the other end of the diode D30 is connected with the output end of the voltage stabilizing unit. The negative electrode of the diode D30 and the other output end of the voltage stabilization unit are connected with the input end of the inversion sub-circuit and the input end of the voltage reduction and transformation sub-circuit. According to the utility model, the time fault can be rapidly positioned, the efficiency of fault maintenance is improved, and normal operation of other equipment is ensured at the same time.

Description

A DC power distribution current protection circuit Technical Field

[0001] This utility model belongs to the field of DC power distribution technology, and specifically relates to a DC power distribution current protection circuit. Background Technology

[0002] Current shipboard electrical systems generally adopt an AC power distribution architecture. The core power supply mode is as follows: the electrical energy output from the diesel AC generator set is converted by a transformer and then supplied to all ship loads through a tiered AC distribution cabinet and cable network. A typical system consists of multiple diesel generators connected in parallel, a main switchboard, a transformer, and various AC or DC electrical equipment. Converters are typically used to power the AC or DC equipment. However, existing converters cannot quickly detect and isolate faults caused by overcurrent, affecting the normal operation of the AC or DC equipment. Summary of the Invention

[0003] Purpose of the utility model: To provide a DC power distribution current protection circuit that solves the above-mentioned problems existing in the prior art.

[0004] Technical Solution: A DC power distribution current protection circuit includes at least two sets of rectifier circuits. The input terminal of each rectifier circuit is connected to the output terminal of a generator. The output terminal of each rectifier circuit is connected to the input terminals of an inverter circuit and a step-down transformer circuit, respectively. Isolating switches are connected between each of the rectifier circuit, inverter circuit, and step-down transformer circuit. The output terminal of the inverter circuit is connected to an AC load device to supply power to the AC device. The output terminal of the step-down transformer circuit is connected to a DC load device to supply power to the DC device. Each rectifier circuit includes a voltage regulator unit. The input terminal of the voltage regulator unit is connected to the output terminal of the generator. One output terminal of the voltage regulator unit is connected to one end of a relay J1. The other end of the relay J1 is connected to the positive terminal of a diode D30. The negative terminal of the diode D30 and the other output terminal of the voltage regulator unit are connected to the input terminals of the inverter circuit and the step-down transformer circuit.

[0005] Preferably, the voltage regulation unit includes inductors L1, L2, and L3, and six sets of on / off voltage regulation modules. The input terminals of inductors L1, L2, and L3 are respectively connected to the output terminals of the generator. The output terminals of inductors L1, L2, and L3 are respectively connected to the input terminals of the on / off voltage regulation modules. The output terminals of three sets of on / off voltage regulation modules are simultaneously connected to the input terminal of relay J1, and the output terminals of the other three sets of on / off voltage regulation modules are simultaneously connected to and serve as the output terminals of the voltage regulation unit.

[0006] Preferably, one of the voltage regulator modules includes a transistor Q1, a diode D1, and a thyristor S1. The emitter of the transistor Q1 is connected to the anode of the diode D1, the cathode of the diode D1 is connected to the anode of the thyristor S1, and the cathode of the thyristor S1 is connected to both the collector of the transistor Q1 and an inductor.

[0007] Preferably, the inverter sub-circuit includes a relay J2, a capacitor C1, six sets of inverter modules, an inductor L4, an inductor L5, and an inductor L6. The input terminal of the rectifier sub-circuit is simultaneously connected to the input terminal of the relay J2, one end of the capacitor C1, and the input terminal of one set of inverter modules. The output terminal of the relay J2 is simultaneously connected to the other end of the capacitor C1 and the input terminal of one set of inverter modules. The inverter modules are connected in series in pairs and then in parallel to form three outputs. The three outputs are respectively connected to one end of inductor L4, inductor L5, and inductor L6. The other end of inductor L4 is simultaneously connected to capacitor C4 and an AC load device. The other end of inductor L5 is simultaneously connected to one end of capacitor C3 and an AC load device. The other end of inductor L6 is simultaneously connected to capacitor C2 and an AC load device. The other end of capacitor C2 is simultaneously connected to capacitor C3 and capacitor C4.

[0008] Preferably, the step-down transformer sub-circuit includes a primary DC bus region, a transformer T1, and a secondary DC bus region. The input terminal of the primary DC bus region is connected to the output terminal of the rectifier sub-circuit, the output terminal of the primary DC bus region is connected to the input terminal of the transformer T1, the output terminal of the transformer T1 is connected to the input terminal of the secondary DC bus region, and the output terminal of the secondary DC bus region is connected to the DC load device.

[0009] Preferably, the primary DC bus region includes diode D19, inductor L7, capacitor C5, resistor R1, thyristor S19, thyristor S20, thyristor S21, and thyristor S22. The output terminal of the rectifier circuit is connected to the positive terminal of diode D19, one end of capacitor C5, the cathode of thyristor S19, and the cathode of thyristor S20, respectively. The negative terminal of diode D19 is connected to one end of inductor L7. The other end of inductor L7 is simultaneously connected to one end of resistor R1, the anode of thyristor S21, and the anode of thyristor S22. The cathode of thyristor S21 is simultaneously connected to the anode of thyristor S19 and pin 2 of transformer T1. The cathode of thyristor S22 is simultaneously connected to the anode of thyristor S20 and pin 1 of transformer T1.

[0010] Preferably, the secondary DC bus region includes diodes D31, D32, D33, D34, inductor L7, diode D35, and capacitor C6. The anode of diode D31 is simultaneously connected to the cathode of diode D33 and pin 3 of transformer T1. The cathode of diode D31 is simultaneously connected to the cathode of diode D32 and one end of inductor L7. The anode of diode D33 is simultaneously connected to the anode of diode D34, one end of capacitor C6, and the power supply terminal of the DC load device. The anode of diode D32 is simultaneously connected to the cathode of diode D34 and pin 4 of transformer T1. The other end of inductor L7 is connected to the anode of diode D35. The cathode of diode D35 is simultaneously connected to the other end of capacitor C6 and the power supply input terminal of the DC load device.

[0011] Beneficial effects: This utility model relates to a DC power distribution current protection circuit, which uses two sets of generators connected to two sets of rectifier circuits to realize two sets of power supply lines. In the event of a fault, the faulty part is isolated by a disconnecting switch, and the other set of generators, together with the inverter circuit and the step-down transformer circuit, are used to supply power to the DC or AC load. The relays installed in the rectifier circuit and the inverter circuit are used to detect and interrupt the fault current, which can quickly locate the fault, improve the efficiency of fault repair, and ensure the normal operation of other equipment. Attached Figure Description

[0012] Figure 1 is a circuit diagram of this utility model. Detailed Implementation

[0013] As shown in Figure 1, this utility model provides a technical solution: a DC power distribution current protection circuit, including at least two sets of rectifier sub-circuits. In this embodiment, two sets of rectifier sub-circuits are used. The input terminal of each set of rectifier sub-circuits is connected to the output terminal of the generator. The output terminal of the rectifier sub-circuit is connected to the input terminal of the inverter sub-circuit and the input terminal of the step-down transformer sub-circuit, respectively. Isolating switches are connected between the rectifier sub-circuit, the inverter sub-circuit, and the step-down transformer sub-circuit. That is, when a fault occurs, the faulty sub-circuit is isolated by the isolating switch to ensure the normal operation of other equipment.

[0014] The output of the inverter sub-circuit is connected to an AC load device to supply power to the AC device. The output of the buck transformer sub-circuit is connected to a DC load device to supply power to the DC device. The rectifier sub-circuit includes a voltage regulator unit. The input of the voltage regulator unit is connected to the output of the generator. One output of the voltage regulator unit is connected to one end of a relay J1. The other end of the relay J1 is connected to the positive terminal of a diode D30. The negative terminal of the diode D30 and the other output of the voltage regulator unit are connected to the inputs of the inverter sub-circuit and the buck transformer sub-circuit. The voltage regulator unit includes inductors L1, L2, and L3, and six sets of on / off voltage regulator modules. The inputs of inductors L1, L2, and L3 are respectively connected to the output of the generator. The outputs of inductors L1, L2, and L3 are respectively connected to... The input terminals of the on / off voltage regulator modules are connected to the input terminals of three sets of on / off voltage regulator modules simultaneously. The output terminals of the other three sets of on / off voltage regulator modules are also connected and serve as the output terminals of the voltage regulator unit. One of the voltage regulator modules includes a transistor Q1, a diode D1, and a thyristor S1. The emitter of the transistor Q1 is connected to the anode of the diode D1, the cathode of the diode D1 is connected to the anode of the thyristor S1, and the cathode of the thyristor S1 is connected to both the collector of the transistor Q1 and an inductor. Through the cooperation of the voltage regulator modules, a stable power supply is provided to the load equipment. When one of the rectifier circuits fails, the relay J1 detects and determines the fault on the DC bus. After the fault reaches a threshold, the relay J1 disconnects, shutting down the rectifier circuit, thus isolating the faulty rectifier circuit. The other set of rectifier circuits, in conjunction with the generator, then supplies power to the load equipment.

[0015] In a further embodiment, the inverter sub-circuit includes a relay J2, a capacitor C1, six sets of inverter modules, an inductor L4, an inductor L5, and an inductor L6. The input terminal of the rectifier sub-circuit is simultaneously connected to the input terminal of the relay J2, one end of the capacitor C1, and the input terminal of one set of inverter modules. The output terminal of the relay J2 is simultaneously connected to the other end of the capacitor C1 and the input terminal of one set of inverter modules. The inverter modules are connected in series in pairs and then in parallel to form three outputs. The three outputs are respectively connected to one end of inductor L4, inductor L5, and inductor L6. The other end of inductor L4 is simultaneously connected to capacitor C4 and an AC load device. The other end of inductor L5 is simultaneously connected to one end of capacitor C3 and an AC load device. The other end of inductor L6 is simultaneously connected to capacitor C2 and an AC load device. The other end of capacitor C2 is simultaneously connected to capacitor C3 and capacitor C4.

[0016] In a further embodiment, the step-down transformer sub-circuit includes a primary DC bus region, a transformer T1, and a secondary DC bus region. The input terminal of the primary DC bus region is connected to the output terminal of the rectifier sub-circuit. The output terminal of the primary DC bus region is connected to the input terminal of the transformer T1. The output terminal of the transformer T1 is connected to the input terminal of the secondary DC bus region. The output terminal of the secondary DC bus region is connected to a DC load device. The primary DC bus region includes a diode D19, an inductor L7, a capacitor C5, a resistor R1, thyristors S19, S20, S21, and S22. The output terminal of the rectifier sub-circuit is connected to the anode of diode D19, one end of capacitor C5, the cathode of thyristor S19, and the cathode of thyristor S20, respectively. The cathode of diode D19 is connected to one end of inductor L7. The other end of inductor L7 is simultaneously connected to one end of resistor R1, the anode of thyristor S21, and the anode of thyristor S22. The cathode of thyristor S22 is simultaneously connected to the anode of thyristor S20 and pin 1 of transformer T1. The secondary DC bus section includes diodes D31, D32, D33, D34, inductor L7, diode D35, and capacitor C6. The anode of diode D31 is simultaneously connected to the cathode of diode D33 and pin 3 of transformer T1. The cathode of diode D31 is simultaneously connected to the cathode of diode D32 and one end of inductor L7. The anode of diode D33 is simultaneously connected to the anode of diode D34, one end of capacitor C6, and the power supply terminal of the DC load device. The anode of diode D32 is simultaneously connected to the cathode of diode D34 and pin 4 of transformer T1. The other end of inductor L7 is connected to the anode of diode D35. The cathode of diode D35 is simultaneously connected to the other end of capacitor C6 and the power supply input terminal of the DC load device.

[0017] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details of the above embodiments. Within the scope of the technical concept of the present invention, various equivalent transformations can be made to the technical solutions of the present invention, and all such equivalent transformations fall within the protection scope of the present invention.

Claims

1. A DC power distribution current protection circuit, characterized in that, The device includes at least two rectifier circuits. The input of each rectifier circuit is connected to the output of a generator. The output of each rectifier circuit is connected to the input of an inverter circuit and the input of a buck transformer circuit, respectively. Isolating switches are connected between the rectifier circuit, the inverter circuit, and the buck transformer circuit. The output of the inverter circuit is connected to an AC load device to supply power to the AC device. The output of the buck transformer circuit is connected to a DC load device to supply power to the DC device. Each rectifier circuit includes a voltage regulator unit. The input of the voltage regulator unit is connected to the output of the generator. One output of the voltage regulator unit is connected to one end of a relay J1. The other end of the relay J1 is connected to the anode of a diode D30. The cathode of the diode D30 and the other output of the voltage regulator unit are connected to the inputs of the inverter circuit and the buck transformer circuit.

2. The DC power distribution current protection circuit according to claim 1, characterized in that, The voltage regulation unit includes inductors L1, L2, and L3, and six sets of on / off voltage regulation modules. The input terminals of inductors L1, L2, and L3 are respectively connected to the output terminals of the generator. The output terminals of inductors L1, L2, and L3 are respectively connected to the input terminals of the on / off voltage regulation modules. The output terminals of three sets of on / off voltage regulation modules are also connected to the input terminal of relay J1, and the output terminals of the other three sets of on / off voltage regulation modules are also connected to and serve as the output terminals of the voltage regulation unit.

3. A DC power distribution current protection circuit according to claim 2, characterized in that, One of the voltage regulator modules includes a transistor Q1, a diode D1, and a thyristor S1. The emitter of the transistor Q1 is connected to the anode of the diode D1, the cathode of the diode D1 is connected to the anode of the thyristor S1, and the cathode of the thyristor S1 is connected to both the collector of the transistor Q1 and an inductor.

4. A DC power distribution current protection circuit according to claim 1, characterized in that, The inverter sub-circuit includes a relay J2, a capacitor C1, six sets of inverter modules, inductors L4, L5, and L6. The input terminal of the rectifier sub-circuit is simultaneously connected to the input terminal of the relay J2, one end of the capacitor C1, and the input terminal of one set of inverter modules. The output terminal of the relay J2 is simultaneously connected to the other end of the capacitor C1 and the input terminal of one set of inverter modules. The inverter modules are connected in series in pairs and then in parallel to form three outputs. The three outputs are respectively connected to one end of inductors L4, L5, and L6. The other end of inductor L4 is simultaneously connected to capacitor C4 and an AC load device. The other end of inductor L5 is simultaneously connected to one end of capacitor C3 and an AC load device. The other end of inductor L6 is simultaneously connected to capacitor C2 and an AC load device. The other end of capacitor C2 is simultaneously connected to capacitors C3 and C4.

5. A DC power distribution current protection circuit according to claim 1, characterized in that, The step-down transformer sub-circuit includes a primary DC bus region, a transformer T1, and a secondary DC bus region. The input terminal of the primary DC bus region is connected to the output terminal of the rectifier sub-circuit. The output terminal of the primary DC bus region is connected to the input terminal of the transformer T1. The output terminal of the transformer T1 is connected to the input terminal of the secondary DC bus region. The output terminal of the secondary DC bus region is connected to the DC load device.

6. A DC power distribution current protection circuit according to claim 5, characterized in that, The primary DC bus region includes diode D19, inductor L7, capacitor C5, resistor R1, thyristor S19, thyristor S20, thyristor S21, and thyristor S22. The output terminal of the rectifier circuit is connected to the positive terminal of diode D19, one end of capacitor C5, the cathode of thyristor S19, and the cathode of thyristor S20, respectively. The negative terminal of diode D19 is connected to one end of inductor L7. The other end of inductor L7 is simultaneously connected to one end of resistor R1, the anode of thyristor S21, and the anode of thyristor S22. The cathode of thyristor S21 is simultaneously connected to the anode of thyristor S19 and pin 2 of transformer T1. The cathode of thyristor S22 is simultaneously connected to the anode of thyristor S20 and pin 1 of transformer T1.

7. A DC power distribution current protection circuit according to claim 5, characterized in that, The secondary DC bus section includes diodes D31, D32, D33, D34, inductor L7, diode D35, and capacitor C6. The anode of diode D31 is simultaneously connected to the cathode of diode D33 and pin 3 of transformer T1. The cathode of diode D31 is simultaneously connected to the cathode of diode D32 and one end of inductor L7. The anode of diode D33 is simultaneously connected to the anode of diode D34, one end of capacitor C6, and the power supply terminal of the DC load device. The anode of diode D32 is simultaneously connected to the cathode of diode D34 and pin 4 of transformer T1. The other end of inductor L7 is connected to the anode of diode D35. The cathode of diode D35 is simultaneously connected to the other end of capacitor C6 and the power supply input terminal of the DC load device.

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