CN204046152U - A kind of zero voltage protection warning circuit - Google Patents

Abstract

A zero-voltage protection alarm circuit is connected to a voltage transformer installed on the 10kV side of a 35 kV substation. The zero-voltage protection alarm circuit includes an alarm circuit, a signal circuit and an RTU accident general signal circuit. When a single-phase grounding or two-phase short-circuit grounding fault occurs in the outgoing line, the alarm circuit is connected, and then the signal circuit is connected, and the RTU accident general signal circuit is triggered to send a fault signal. The utility model is used to protect and alarm the temporary power supply on the 10kV side when the 10kV part of the 35kV substation is transformed, so as to ensure the safe operation of the system.

Description

A zero voltage protection alarm circuit

technical field

The utility model relates to a zero-voltage protection alarm circuit.

Background technique

As shown in Figure 1, when the 10kV part of the neutral point ungrounded 35kV substation 1 is transformed, in order not to affect the user's power supply, it is generally necessary to cut over the 10kV side of the main transformer 1 to the erected temporary power supply measures to carry out load monitoring. powered by. This temporary power supply method needs to be equipped with a set of zero-voltage protection and alarm system, so that when a single-phase grounding or two-phase short-circuit grounding fault occurs on the outgoing line of each 10kV side, a protection alarm can be issued in time.

Utility model content

The utility model provides a zero-voltage protection alarm circuit, which is used to protect and alarm the temporary power supply on the 10kV side when the 10kV part of the 35kV substation is transformed, so as to ensure the safe operation of the system.

In order to achieve the above purpose, the utility model provides a zero-voltage protection alarm circuit, which is connected to a voltage transformer arranged on the 10kV side of a 35 kV substation, and the voltage transformer includes a primary side of the voltage transformer and a secondary side of a voltage transformer, wherein the secondary side of the voltage transformer includes a star winding and an open delta winding;

The zero-voltage protection alarm circuit includes an alarm circuit, a signal circuit and an RTU accident general signal circuit;

The alarm circuit includes a delay voltage relay JYS, and a warning light connected in series with the contact JYS-1 of the delay voltage relay JYS; the delay voltage relay JYS is connected in parallel to the open delta connection of the voltage transformer On the secondary side, the contact JYS-1 is connected to the positive power supply +XM of the signal power supply, and the warning light is connected to the small signal busbar 1SYM;

The signal circuit includes a series impact relay and an intermediate relay 2ZJ; the impact relay is connected to the small signal bus 1SYM, and the intermediate relay 2ZJ is connected to the negative power supply of the signal power supply -XM;

The RTU accident total signal circuit includes a contact 2ZJ-1 of the intermediate relay 2ZJ; the contact 2ZJ-1 is connected to the first RTU access terminal and the RTU second access terminal.

The primary side of the voltage transformer is electrically connected to the 10kV side of the 35kV substation 1 through a fuse.

The positive power supply +XM of the signal power supply and the negative power supply -XM of the signal power supply are drawn from the DC screen in the substation.

The positive power supply +XM of the signal power supply provides a voltage of +55V, and the negative power supply of the signal power supply -XM provides a voltage of -55V.

The signal small busbar 1SYM, the positive power supply +XM of the signal power supply and the negative power supply -XM of the signal power supply are laid side by side in the small busbar compartment on the top of each control panel in the control room of the substation.

The signal small busbar 1SYM is laid with copper rods.

The RTU first access terminal and the RTU second access terminal are two wires led out from the RTU device, which respectively correspond to an input contact of an RTU.

The first access terminal of the RTU has a voltage of 24V, and the second access terminal of the RTU is not charged when the contact 2ZJ-1 of the intermediate relay is not closed. After the contact 2ZJ-1 is closed, the first access terminal of the RTU and the second access terminal of the RTU The access terminals are connected, and the second access terminal of the RTU also carries a voltage of 24V.

The utility model is used to protect and alarm the temporary power supply on the 10kV side when the 10kV part of the 35kV substation is transformed, so as to ensure the safe operation of the system.

Description of drawings

Fig. 1 is a schematic diagram of temporary power supply on the 10kV side of a 35kV substation in the background technology.

Fig. 2 is a schematic circuit diagram of a voltage transformer on the 10kV side of a 35kV substation.

Fig. 3 is a schematic circuit diagram of an alarm circuit of the zero-voltage protection alarm circuit provided by the present invention.

Fig. 4 is a schematic circuit diagram of the signal loop of the zero-voltage protection alarm circuit provided by the present invention.

Fig. 5 is a schematic circuit diagram of the RTU accident general signal loop of the zero-voltage protection alarm circuit provided by the utility model.

Detailed ways

The preferred embodiment of the present utility model will be described in detail below according to Fig. 2 to Fig. 5 .

As shown in Figure 2, since the 10kV part of the 35kV substation 1 is being remodeled, and the temporary measure for the line to continue running lacks the function of a voltage transformer, a voltage transformer 3 is temporarily installed on the 10kV side, and measured through the voltage transformer 3 primary side voltage. The voltage transformer 3 is a JDZ-10 dry-type epoxy resin insulated voltage transformer with a rated voltage ratio of (10/√3)/(0.1/√3)/(0.1/3), and the primary side of the voltage transformer is 31 It is connected to the 10kV side of the 35 kV substation 1 through the fuse 2 (type RN2, rated current 2A). The secondary side 32 of the voltage transformer includes a star winding 3202 and an open delta winding 3201. The secondary side of the star winding 3202 Measure the three-phase voltage of A, B, and C for use by other equipment, and the secondary side of the open delta winding 3201 is used for the zero voltage alarm circuit.

The zero-voltage protection alarm circuit provided by the utility model is connected to the secondary side of the open triangle winding 3201 of the voltage transformer 3, and the zero-voltage protection alarm circuit includes an alarm circuit, a signal circuit and an RTU (Remote Terminal Unit) accident general signal circuit.

As shown in Fig. 2 and Fig. 3, described warning circuit comprises time-delay voltage type relay JYS, and the warning light 101 connected in series with the contact JYS-1 of time-delay voltage type relay JYS; Described time-delay voltage type relay JYS Parallel connected to the secondary side of the open delta connection 3201 of the voltage transformer 3, the contact JYS-1 is connected to the positive power supply +XM of the signal power supply, and the warning light 101 is connected to the small signal bus 1SYM.

The time-delayed voltage relay JYS is used to detect zero-sequence voltage.

As shown in FIG. 4 , the signal loop includes a series connection of impact relay 102 and intermediate relay 2ZJ; the impact relay 102 is connected to the small signal bus 1SYM, and the intermediate relay 2ZJ is connected to the signal power negative power supply -XM.

As shown in FIG. 5 , the RTU accident general signal circuit includes the contact 2ZJ-1 of the intermediate relay 2ZJ; the contact 2ZJ-1 is connected to the RTU first access terminal 801 and the RTU second access terminal 843 .

The positive power supply +XM of the signal power supply and the negative power supply -XM of the signal power supply are drawn from the DC screen in the substation (the DC screen in the substation provides the power supply for each control and protection equipment, and one of them is called "signal power supply" for power supply. Various signaling devices), the positive power supply +XM of the signal power supply provides +55V voltage, the negative power supply of the signal power supply -XM provides the voltage of -55V; Power supply +XM and signal power supply negative power supply -XM are laid side by side in the small busbar compartment on the top of each control panel in the control room of the substation, generally using copper rods for laying; the first RTU access terminal 801 and the RTU second access terminal Terminal 843 is two wires drawn from the RTU device, which correspond to an input contact of an RTU respectively, wherein, the first access terminal 801 of the RTU has a voltage of 24V, and the second access terminal 843 of the RTU is connected to the contact 2ZJ-1 of the intermediate relay. When closed, there is no charge. After the contact 2ZJ-1 is closed, the RTU first access terminal 801 and the RTU second access terminal 843 are connected, and the RTU second access terminal 843 also carries a voltage of 24V.

During normal operation, the primary side 31 of the voltage transformer collects the voltage on the 10kV side of the main transformer through the voltage transformer fuse 2. At this time, the voltage on the 10kV primary side of the transformer is a three-phase balanced 10kV voltage (A, B, C three-phase phase voltage is 10/√3 kV), when reflected to the secondary side 32 of the voltage transformer, the star winding 3202 on the secondary side 32 of the voltage transformer measures a three-phase balanced 100 volt voltage (A, B, The phase voltages of the three phases C are all 10/√3 volts), and the voltage measured by the open delta winding 3201 on the secondary side 32 of the voltage transformer is 0 volts (the three-phase voltages of A, B, and C are symmetrical, and the total voltage after the open connection close to 0 volts). The opening voltage of the open delta winding side of the voltage transformer 3 is close to 0 volts, which has not reached the trigger value of the delay voltage relay JYS, and the contact JYS-1 of the delay voltage relay does not act and remains normally open, that is, the alarm circuit is blocked , the left side of the warning lamp 101 is not charged (the warning lamp is not lit), the small signal bus 1SYM is not charged, the impact relay 102 is not sounded, and the left side of the intermediate relay 2ZJ is not charged, so it does not form a circuit and does not act. Contact 2ZJ-1 is not closed, so the RTU accident general signal circuit is blocked, and the RTU accident general signal alarm is not performed.

When a single-phase grounding or two-phase short-circuit grounding fault occurs on the 10kV line outlet of the 35 kV substation, the voltage on the primary side 31 of the voltage transformer is greatly reduced by one phase or two phases, and the opening voltage on the side of the open delta winding 3201 increases. After the opening voltage rises to the trigger value of the delay voltage relay JYS and lasts for a set time (in this embodiment, the trigger value is 25V, and the duration is set to 3 seconds), the delay voltage relay YJS is triggered, and its The contact JYS-1 is closed, the alarm circuit is connected, and the +55V voltage on the positive power supply +XM of the signal power supply is transmitted to the left side of the warning light through the contact JYS-1, and the warning light is turned on, indicating that a single-phase or two-phase short circuit has occurred in the line. Fault, the signal small bus 1SYM is electrified +55V, and at the same time, the signal small bus 1SYM is electrified +55V and forms a circuit with the negative power supply of the signal power supply -XM bus (charged -55V), the impact relay 102 acts, and triggers the coil of the intermediate relay 2ZJ, so that The normally open contact 2ZJ-1 of the intermediate relay is closed, the second access terminal 843 of the RTU carries +24V voltage (the first access terminal 801 of the RTU always carries +24V voltage), triggers the RTU accident general signal, and dispatches through the RTU to receive the relevant The alarm signal reminds the operator that a fault occurs in the substation. It is suspected that it is a ground fault on the line. It is necessary to inspect the line, and then find the fault point in time, eliminate the ground fault, and protect the safe operation of the system.

Although the content of the present invention has been described in detail through the above preferred embodiments, it should be recognized that the above description should not be considered as a limitation of the present invention. Various modifications and substitutions of the present utility model will be obvious to those skilled in the art after reading the above content. Therefore, the protection scope of the present utility model should be defined by the appended claims.

Claims (8)

1. A zero-voltage protection alarm circuit, the zero-voltage protection alarm circuit is connected to a voltage transformer (3) arranged on the 10kV side of a 35 kV substation, and the voltage transformer (3) includes the primary side of the voltage transformer ( 31) and a voltage transformer secondary side (32), wherein the voltage transformer secondary side (32) includes a star winding (3202) and an open delta winding (3201); It is characterized in that the zero-voltage protection alarm circuit includes an alarm loop, a signal loop and an RTU accident general signal loop; The alarm circuit includes a delay voltage relay JYS, and a warning light (101) connected in series with the contact JYS-1 of the delay voltage relay JYS; the delay voltage relay JYS is connected in parallel to the voltage transformer (3 ) on the secondary side of the open triangle connection (3201), the contact JYS-1 is connected to the positive power supply +XM of the signal power supply, and the warning light (101) is connected to the small signal busbar 1SYM; The signal circuit includes a series impact relay (102) and an intermediate relay 2ZJ; the impact relay (102) is connected to the small signal bus 1SYM, and the intermediate relay 2ZJ is connected to the negative power supply of the signal power supply -XM; The RTU accident general signal circuit includes the contact 2ZJ-1 of the intermediate relay 2ZJ; the contact 2ZJ-1 is connected to the first RTU access terminal (801) and the RTU second access terminal (843). 2. The zero-voltage protection alarm circuit according to claim 1, characterized in that, the primary side (31) of the voltage transformer is electrically connected to the 10kV side of the 35kV substation 1 through a fuse (2). 3. The zero-voltage protection alarm circuit according to claim 1, wherein the positive power supply +XM of the signal power supply and the negative power supply -XM of the signal power supply are drawn from the DC screen in the substation. 4. The zero-voltage protection alarm circuit according to claim 3, wherein the positive power supply +XM of the signal power supply provides a voltage of +55V, and the negative power supply of the signal power supply -XM provides a voltage of -55V. 5. The zero-voltage protection alarm circuit according to claim 3 or 4, characterized in that, the signal small busbar 1SYM, the positive power supply +XM of the signal power supply and the negative power supply -XM of the signal power supply are laid side by side in the control room in the substation Inside the small bus compartment on the top of each control panel. 6. The zero-voltage protection alarm circuit according to claim 5, characterized in that, said small signal busbar 1SYM is laid with copper rods. 7. The zero-voltage protection alarm circuit according to claim 6, characterized in that, the RTU first access terminal (801) and the RTU second access terminal (843) are two wires drawn from the RTU device , respectively corresponding to the input contacts of an RTU. 8. The zero-voltage protection alarm circuit according to claim 7, characterized in that, the first access terminal (801) of the RTU has a voltage of 24V, and the second access terminal (843) of the RTU is at the contact point of the intermediate relay When 2ZJ-1 is not closed, it is not charged. After the contact 2ZJ-1 is closed, the first RTU access terminal (801) and the RTU second access terminal (843) are connected, and the RTU second access terminal (843) also carries a voltage of 24V. .