Low-voltage direct-current current-limiting circuit breaker with adjustable current-limiting capability

Abstract

The utility model discloses a low-voltage DC current-limiting circuit breaker with adjustable current-limiting capability, which comprises a power supply, the power supply is connected with an adjustable resistor module through a line L1, the adjustable resistor module is connected with a circuit breaker, the circuit breaker is connected with a current-limiting circuit breaker through a line L2, and the adjustable resistor module is a slot type resistor. According to the low-voltage direct-current current-limiting circuit breaker with the adjustable current-limiting capability, a resistor element is adopted for current limiting, a current-limiting resistor slot is arranged inside, the resistance value is marked outside an insertion piece, resistors can be independently inserted into two poles, the resistance values of the resistors are different, the output current of the current-limiting circuit breaker is matched with different resistor modules according to the level difference, and the purpose of adjusting the current-limiting capability is achieved; the current-limiting circuit breaker can effectively solve the problem that stage difference matching of a current direct-current power supply system is difficult, selectivity of each stage of switch can be guaranteed, operation safety of a direct-current system is enhanced, and electric energy loss is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of a low-voltage direct current limiting circuit breaker with adjustable current limiting capacity. Background Art

[0002] A current limiting circuit breaker is a circuit breaker with a breaking time short enough to break before the short-circuit current reaches its expected peak value. Its principle is that when a short-circuit fault occurs, the contacts open quickly and an arc is generated, which is equivalent to inserting a rapidly increasing arc voltage in series in the line, thereby limiting the fault current.

[0003] The current DC power supply system has the problem of difficult level matching. When the short-circuit current is high and close to its expected peak value, the switches at each level frequently trip, the contacts open quickly, and an arc is generated. When the large current is interrupted, the contacts are easily burned and damaged. The main line current cannot be allocated according to the circuit current and the switches cannot be matched. The selectivity of the switches at each level cannot be guaranteed, resulting in the safety analysis of the operation of the DC system. Therefore, an adjustable DC circuit breaker is proposed to solve the above problems. Utility Model Content

[0004] The purpose of the utility model is to provide a low-voltage DC current limiting circuit breaker with adjustable current limiting capability to solve the problems raised in the above background technology.

[0005] In order to achieve the above purpose, the utility model provides the following technical solutions:

[0006] A low-voltage DC current limiting circuit breaker with adjustable current limiting capacity comprises a power supply, wherein the power supply is connected to an adjustable resistance module via a line L1, the adjustable resistance module is connected to a circuit breaker, and the circuit breaker is connected to the current limiting circuit breaker via a line L2.

[0007] As a further solution of the utility model: the adjustable resistance module is a slot-type resistor, which is mainly composed of a socket and a resistor, and the resistor is set to F1, F2 and Fn according to the resistance value.

[0008] As a further solution of the utility model: the adjustable resistance module is connected in parallel with the current circuit breaker, and when the adjustable resistance module is replaced, the current circuit breaker closes to short-circuit the adjustable resistance module.

[0009] As a further solution of the utility model: the adjustable resistance modules are resistors connected in series, and the resistors are set to F1, F2 and Fn according to the resistance values.

[0010] As a further solution of the utility model: the adjustable resistance module is connected in parallel with the resistance control circuit, the resistance control circuit is composed of current circuit breakers, and each resistor is connected in parallel with a group of current circuit breakers.

[0011] As a further solution of the utility model: the end of the line L2 is a common wiring port, the common wiring port is connected to a plurality of current limiting circuit breakers, and the output currents of the current limiting circuit breakers are 1A, 2A, 3A and nA respectively.

[0012] Compared with the prior art, the beneficial effects of the utility model are:

[0013] 1. The low-voltage DC current limiting circuit breaker with adjustable current limiting capacity adopts resistance elements for current limiting. A current limiting resistor slot is provided inside. The resistance value is marked on the outside of the plug. Resistors can be inserted independently at both poles. The resistance values ​​of the resistors are different. The output current of the current limiting circuit breaker is matched with different adjustable resistance modules according to the level difference to achieve the purpose of adjustable current limiting capacity. The current limiting circuit breaker can effectively solve the problem of level difference matching difficulties in the current DC power supply system. The selectivity of switches at all levels can be guaranteed, which enhances the operating safety of the DC system and reduces energy loss.

[0014] 2. This low-voltage DC current limiting circuit breaker with adjustable current limiting capacity has a current limiting resistor slot inside. The circuit can be switched as needed to allow the current to pass through resistors of different resistance values, solving the problem of difficult level matching in the current DC power supply system. The selectivity of switches at each level can be guaranteed, enhancing the operating safety of the DC system and reducing energy loss. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a structural schematic diagram of a first embodiment of a low-voltage DC current limiting circuit breaker with adjustable current limiting capability;

[0016] Figure 2 The diagram is a structural diagram of a second embodiment of a low-voltage DC current limiting circuit breaker with adjustable current limiting capability.

[0017] In the figure: 1. power supply; 2. line L1; 3. adjustable resistance module; 4. current circuit breaker; 5. circuit breaker; 6. line L2; 7. current limiting circuit breaker. DETAILED DESCRIPTION

[0018] Embodiment 1

[0019] See also Figure 1In an embodiment of the utility model, a low-voltage DC current limiting circuit breaker with adjustable current limiting capacity includes a power supply 1, the power supply 1 is connected to an adjustable resistance module 3 through a line L1 2, the adjustable resistance module 3 is connected to a circuit breaker 5, the circuit breaker 5 is connected to a current limiting circuit breaker 7 through a line L2 6, the adjustable resistance module 3 is a slot-type resistor, the slot-type resistor is mainly composed of a socket and a resistor, the resistor is set to F1, F2 and Fn according to the resistance value, and is used in a DC system of 220V and below in a substation, and a resistance element is used for current limiting. A current limiting resistor slot is set inside, and a resistor of a corresponding resistance value can be inserted as needed. The resistance value is marked on the outside of the plug, and resistors can be inserted independently at both poles. The resistance values ​​of F1, F2 and Fn can be divided into sequences of 0.05, 0.1, 0.2, 0.3, 0.4, 0.5, etc., and the total resistance value is 0.05-1Ω. The resistor adopts an external screw crimping method to ensure the reliability of the connection. The adjustable resistance module has a measuring hole, which is convenient In the later operation and maintenance process, it is detected whether the resistor fails. The current limiting circuit breaker 7 can effectively solve the problem of difficult level matching of the current DC power supply system. The selectivity of the switches at each level can be guaranteed, which enhances the operation safety of the DC system. In order to reduce the power loss, only the low-voltage DC current limiting circuit breaker is used in the DC terminal circuit, that is, only the S3 circuit breaker uses the current limiting circuit breaker 7 to reduce the short-circuit current at d3, thereby reducing the size of the S2 switch, and further reducing the cross-sectional area of ​​the L2 loop conductor, reducing copper loss. Since the normal operating current of each DC terminal feeder circuit is very small, generally between 0.2-0.5A, the introduced resistance power consumption is generally not more than 0.25W and can be ignored.

[0020] In a preferred embodiment, the adjustable resistance module 3 is connected in parallel with a resistance control circuit, and the resistance control circuit is composed of a current circuit breaker 4. Each resistor is connected in parallel with a group of current circuit breakers 4. Before the adjustable resistance module 3 is inserted and replaced, all circuit breakers are closed to short-circuit the adjustable resistance module 3, and replacement of the resistance of the adjustable resistance module 3 is safe and convenient.

[0021] In a preferred embodiment, the end of line L2 6 is a common wiring port, which is connected to multiple current limiting circuit breakers 7. The output currents of the current limiting circuit breakers 7 are 2A, 4A, 6A and nA respectively. The output current of the current limiting circuit breakers 7 is matched with different adjustable resistance modules 3 according to the step difference to achieve the purpose of adjustable current limiting capacity.

[0022] Embodiment 2

[0023] See also Figure 2In an embodiment of the utility model, a low-voltage DC current limiting circuit breaker with adjustable current limiting capacity includes a power supply 1, the power supply 1 is connected to an adjustable resistance module 3 through a line L1 2, the adjustable resistance module 3 is connected to a circuit breaker 5, the circuit breaker 5 is connected to a current limiting circuit breaker 7 through a line L2 6, the adjustable resistance module 3 is a resistor connected in series with each other, the resistor is set to F1, F2 and Fn according to the resistance value, a current limiting resistor slot is arranged inside, the circuit can be switched as needed, so that the current passes through resistors of different numbers of resistance values, the resistance value of a single resistor can be divided into a 0.05 sequence, and the total resistance value is 0.05-1Ω, the resistance value on both sides of the resistor can be measured by following an instrument, so as to facilitate online observation of whether the resistor fails during operation and maintenance, and the current limiting circuit breaker 7 can effectively solve the problem of difficult level matching of the current DC power supply system.

[0024] In a preferred embodiment, the adjustable resistance module 3 is connected in parallel with a resistance control circuit, the resistance control circuit is composed of current circuit breakers 4, and each resistor is connected in parallel with a group of current circuit breakers 4.

[0025] In a preferred embodiment, the end of line L2 6 is a common wiring port, which is connected to a plurality of current limiting circuit breakers 7 , and the output currents of the current limiting circuit breakers 7 are 2A, 4A, 6A and nA respectively.

[0026] It should be noted that the above embodiments all belong to the same utility model concept, and the description of each embodiment has its own focus. For matters that are not described in detail in some embodiments, reference can be made to the description in other embodiments.

[0027] The above-mentioned embodiments only express the implementation methods of the utility model, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the utility model patent. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the utility model, and these all belong to the protection scope of the utility model. Therefore, the protection scope of the utility model patent shall be based on the attached claims.

Claims

1. A low voltage DC current limiting circuit breaker with adjustable current limiting capability, comprising a power supply (1), characterized in that: The power supply (1) is connected to the adjustable resistance module (3) via a line L1 (2), the adjustable resistance module (3) is connected to a circuit breaker (5), and the circuit breaker (5) is connected to a current limiting circuit breaker (7) via a line L2 (6).

2. A low-voltage DC current limiting circuit breaker with adjustable current limiting capacity according to claim 1, characterized in that: The adjustable resistance module (3) is a slot-type resistor, which is mainly composed of a socket and a resistor, and the resistor is set to F1, F2 and Fn according to the resistance value.

3. A low-voltage DC current limiting circuit breaker with adjustable current limiting capacity according to claim 2, characterized in that: The adjustable resistance module (3) is connected in parallel with the current circuit breaker (4); when the adjustable resistance module (3) is replaced, the current circuit breaker (4) closes to short-circuit the adjustable resistance module (3).

4. A low-voltage DC current limiting circuit breaker with adjustable current limiting capacity according to claim 1, characterized in that: The adjustable resistance modules (3) are resistors connected in series, and the resistances are set to F1, F2 and Fn according to the resistance values.

5. A low-voltage DC current limiting circuit breaker with adjustable current limiting capacity according to claim 4, characterized in that: The adjustable resistance module (3) is connected in parallel to a resistance control circuit, the resistance control circuit is composed of current circuit breakers (4), and each resistor is connected in parallel to a group of current circuit breakers (4).

6. A low-voltage DC current limiting circuit breaker with adjustable current limiting capacity according to claim 3 or 4, characterized in that: The end of the line L2 (6) is a common wiring port, which is connected to a plurality of current limiting circuit breakers (7), and the output currents of the current limiting circuit breakers (7) are 2A, 4A, 6A and nA respectively.

Images