CN220439494U

CN220439494U - Improved structure of power protection circuit breaker

Info

Publication number: CN220439494U
Application number: CN202021739209.7U
Authority: CN
Inventors: 黎祥英
Original assignee: Shenzhen Anzu Information Technology Co ltd
Current assignee: Shenzhen Anzu Information Technology Co ltd
Priority date: 2020-08-19
Filing date: 2020-08-19
Publication date: 2024-02-02
Anticipated expiration: 2030-08-19

Abstract

The utility model provides an improvement structure of electricity protection circuit breaker, including the current detection part that has the singlechip, the relay switch of its action of switch circuit control is passed through by the singlechip, the singlechip has such function, when the condition of circuit breaker disconnection appears in the electric wire that current detection part detected, trigger circuit breaking protection procedure, the singlechip delays the settlement time after the power waveform peak appears and sends touch switch signal to switch circuit, makes the relay switch break when the current value on the electric wire is located the zero potential of power waveform or is close zero potential. Compared with the prior art, the utility model has the advantages of low cost, small volume and simple structure, and can avoid generating electric arc when the relay switch is opened.

Description

Improved structure of power protection circuit breaker

Technical Field

The utility model relates to an electric protection technology.

Background

The existing electricity protection circuit breaker (such as a household electricity protection circuit breaker) has the advantages that when the current is larger than a certain value (such as 63A), a power supply is disconnected to protect electricity safety, a switch adopted in the outage is either a relay switch or an air switch, and the relay switch is low in cost, small in size and simple in structure, but when the electricity is disconnected, the electricity is always disconnected under the condition of large current, so that an arc is generated in the moment of disconnection, and serious ablation is generated on a contact by the arc, so that the service life of the electricity protection circuit breaker is greatly shortened; while the air switch is adopted, the generation of electric arc is effectively prevented when the circuit is broken, but the air switch has large volume, complex structure and high cost.

Disclosure of Invention

The utility model aims to provide an improved structure of an electricity protection circuit breaker, which can avoid generating electric arcs when a relay switch is broken, and has the advantages of low cost, small volume and simple structure.

The utility model is realized by the way, the utility model comprises a current detection part with a singlechip and a relay switch which is controlled by the singlechip to act through a switch circuit, wherein the singlechip has the function that when the alternating current on a wire detected by the current detection part is larger than a breaking threshold value and causes a breaking protection program to be triggered, the singlechip delays for a set time t and then sends a triggering switch signal to the switch circuit, so that the relay switch is disconnected when the current value of the alternating current on the wire is positioned near the zero point of a current waveform.

Depending on the configuration of the relay switch, it often takes a period of time t from when the trigger signal is obtained to when the contacts are actually open ₁ (typically, tens of milliseconds, and is generally defined as the intrinsic time of the relay switch action), the time t1 is the intrinsic time of the relay switch action, and the t1 of each relay is not necessarily the same, so that the value is calculated by executing a self-checking program when each product leaves the factory and is stored in a memory of the singlechip. If the protection program is triggered, the singlechip immediately sends an open trigger electric signal to the relay switch, and a period of time t1 is from the time when the relay switch obtains the trigger electric signal to the time when the switch is truly disconnected, so that when the contact is disconnected, the current has high probability of being at a position with larger current in the current waveform, and an arc ablation electrode is generated. The singlechip is adopted to delay for a period of time t and then send a trigger switch electric signal to the switch circuit, thus, the current detection part detects that the current meets the requirement of the circuit breaking protection strip by delayThe time of triggering the open-circuit protection program when the relay switch is started, the time t of delay is added with the time required for the relay switch from the acquisition of the trigger signal to the disconnection of the contact, namely the inherent time t of the relay switch ₁ The current value of the alternating current on the electric wire is just near the zero point of the current waveform, and the current is small to be close to the zero value, so that no arc is generated when the contacts are separated, and the reliability and durability of the electric protection circuit breaker are effectively ensured.

Compared with the prior art, the single chip microcomputer has the advantages of low cost, small volume and simple structure, and can avoid generating electric arcs when the relay switch is disconnected because the relay switch is controlled to be disconnected near the zero value of the current so as to avoid generating the electric arcs.

Drawings

FIG. 1 is a schematic view of the structure of an embodiment 1 of the present utility model;

FIG. 2 is a graph of current waveforms when the relay switch is open;

fig. 3 is a schematic structural diagram of embodiment 2 of the utility model.

Detailed Description

The utility model will now be described in further detail with reference to the accompanying drawings and examples:

example 1: as shown in fig. 1, the utility model comprises a current detection part 2 with a singlechip 1 and a relay switch 4 controlled by the singlechip 1 to act through a switch circuit 3, wherein the singlechip 1 has the function of triggering a circuit breaking protection program when the alternating current on an electric wire 5 detected by the current detection part 2 is abnormal and meets the circuit breaking protection condition, and the singlechip 1 delays for a set time t and then sends a triggering switch electric signal to the switch circuit 3 so as to enable the relay switch 4 to be disconnected at a time near the zero point level of the alternating current waveform on the electric wire 5.

As shown in fig. 2, when the ac current on the electric wire 5 detected by the current detecting portion 2 is abnormal, and the open-circuit protection condition is satisfied, the open-circuit protection program is activated until the current reaches the highest value of the current waveform (i.e., before the peak a, until the peak a, and before the trough b, until the trough b).

The delay time T is a value, t=T/4+ (n is T/2-T1), wherein the value of n is an integer which is more than or equal to 0, T is the period time of alternating current, T1 is the time required for the relay switch to truly disconnect from the touch signal to the contact, namely the inherent time of the relay switch action, and the value is calculated by executing a self-checking program when each product leaves the factory and is stored in a memory of the singlechip.

If the frequency of the mains supply is 50HZ, that is, the time required for one complete waveform is 20 ms, the time required for 1/4 cycle is 5 ms, the time required for 1/2 cycle of the current waveform is 10 ms, and the intrinsic action time t1 of the relay is assumed to be 4ms at the time of leaving the factory.

According to the formula, the delay time t=T/4+ (n is T/2-T1), n takes the value of integers 1, 2 and 3 … … (1 is adopted in n in the embodiment) which enable T to be more than or equal to 0, namely t=20/4+ (0-4) =1 ms, 20/4+ (2*5-4) =11 ms and 20/4+ (3*5-4) =16 ms … …, that is, when the alternating current wave crest appears, the delay time of starting the protection program is 1ms or 11ms or 16ms … …, then the singlechip sends an electric signal of an open circuit instruction to the relay, the intrinsic action time of the relay is 4ms, the former delay time is 1ms or 11ms or 16ms … …, when the time reaches 5 ms or 12ms or 17ms … …, the contact of the relay is just disconnected, the waveform of the alternating current is at zero potential, the arc cannot be generated, and the contact of the relay is protected from the arc erosion.

Therefore, by adopting the above-mentioned method for determining the delay time t, the relay switch 4 can be ensured to be opened within the shortest delay time, and when the contacts are separated, the current value is theoretically just zero (because of the existence of errors, the current value is always a very small current value very close to zero in practice, and because of the small current, no arc can be generated).

Further, the value of n is an integer when 400 ms is greater than or equal to t and equal to 0, and the delay time cannot be too long due to safety consideration, otherwise, safety problems (such as ensuring that the power protection circuit breaker plays a role in safety protection and most countries prescribe t is not more than 400 ms) are generated, so that 400 ms is greater than or equal to t and equal to 0 is set to ensure that the power protection circuit breaker plays a role in safety protection.

Still further, n is the smallest integer that makes t.gtoreq.0. The safety protection function of the electric protection circuit breaker is further improved by adopting the value.

Example 2: as shown in fig. 3, in this embodiment, on the basis of embodiment 1, a temperature and humidity detector 5 is provided near a relay switch 4, and an electrical signal output of the temperature and humidity detector 5 is connected to an electrical signal input of a single chip microcomputer 1.

The delay time T is a value that t=t/4+ (n×t/2-T1), t1=t2+ (T2 is the time required for the relay switch to actually open from the acquisition of the touch signal to the actual opening of the contact at the standard ambient temperature and the standard ambient humidity, and T is the inherent time of the relay switch operation, and T is the deviation amount of T1 from the standard ambient temperature and the standard ambient humidity. The correction is obtained by detection before delivery and is stored in a memory of the singlechip in the form of a data table.

If the frequency of the mains is 50HZ, i.e. the time required for a complete waveform is 20 ms, the time required for 1/4 cycle is 5 ms, the time required for 1/2 cycle of the current waveform is 10 ms, the standard ambient temperature at 25 ℃ and the ambient humidity at 80% T2 are 4ms, the ambient temperature at use detected by the temperature and humidity detector 5 is 30 ℃, the humidity 80%, the corresponding T is-0.4 ms, i.e. t1=t2+ (t=4-0.4=3.6).

According to the formula, the delay time t=T/4+ (n×T/2-T1), n takes the value of the minimum integer 0 which enables T to be more than or equal to 0, namely t=20/4+ (0-3.6) =1.4 ms, namely, when the alternating current wave crest appears, the delay time of starting the protection program is 1.4ms, then the singlechip sends an electric signal of an open circuit instruction to the relay, the inherent action time of the relay is 4ms, the delay time is 1.4ms, when the clock reaches 5.4 ms, the contact of the relay is just disconnected, the waveform of the alternating current is at zero potential at the moment, no arc is generated, and the contact of the relay is protected from arc erosion.

Claims

1. The improved structure of the electric protection circuit breaker is characterized by comprising a current detection part with a singlechip and a relay switch controlled by the singlechip to act through a switch circuit, wherein the singlechip has the functions that when the electricity consumption condition on an electric wire detected by the current detection part is abnormal and the condition of breaking the circuit protection switch is met, a breaking protection program is triggered when the current reaches the highest value of a current waveform, then the singlechip delays for a set time and sends a trigger electric signal to the relay switch circuit, so that the current value of alternating current on the electric wire of the relay switch is disconnected when the current value of the alternating current on the electric wire is positioned at zero potential or near zero potential of a power waveform, the set time T delayed by the singlechip is t=T/4+ (n is T/2-T1), wherein the value condition of n is an integer which is more than or equal to 0, T is the cycle time of alternating current, and T1 is the real time required by the relay switch from obtaining the trigger signal to the contact breaking, namely the intrinsic time of the relay switch action.

2. The improved structure of the electric protection circuit breaker according to claim 1, wherein a temperature and humidity detector is arranged near the relay switch, and an electric signal output of the temperature and humidity detector is connected with an electric signal input of the single chip microcomputer.