1. Application range

This series of zero-sequence over-current and over-voltage relays are used in generators, transformers and power transmission lines as zero-sequence over-current and over-voltage protection.

2. Model definition

3. Working principle and main performance

3.1 Working principle:

The AC voltage or AC current is converted by the converter to the AC voltage required by the series of relays; then the harmonics other than 50HZ are filtered through the 150HZ band stop and 50HZ band pass; then the DC voltage is converted into the setting circuit through rectification and filtering; The loop changes the setting value by changing the magnification of the operational amplifier; the output voltage UZ of the setting loop is compared with the threshold voltage UB through the level detector; then the output of the relay J is driven to act.

3.2 The action process of zero sequence overcurrent and zero sequence overvoltage relay (take AK11 structure relay as an example):

3.2.1 For the zero-sequence over-current relay in normal operation, UZ＜UB, relay J will not operate, the moving contacts 1-3 and 7-19 are disconnected, and the moving breaking contacts 3-17 and 5-7 are closed; In the case of a fault, UZ≥UB, relay J will act, the moving contacts 1-3, 7-19 will be closed, and the moving break contacts 3-17, 5-7 will be disconnected.

3.2.2 For the zero-sequence overvoltage relay in normal operation, UZ＜UB, relay J will not operate, the moving contacts 1-3 and 7-19 are disconnected, and the moving disconnection contacts 3-17 and 5-7 are closed; In the case of a fault, UZ≥UB, relay J will act, the moving contacts 1-3, 7-19 will be closed, and the moving break contacts 3-17, 5-7 will be disconnected.

3.3 The use of high-efficiency integrated circuits and components, with stable performance, high reliability, high accuracy of the action value, small discrete value, wide setting range, fast action and return speed, good return coefficient, small load on the transformer, and vibration resistance , Anti-interference and high insulation level.

3.4 The protection setting value is set by the dial switch on the relay panel, and the setting calculation formula is indicated. The setting is intuitive and convenient, and the debugging is simple and convenient. No adjustment is required on site.

3.5 The product installation structure includes embedded board rear wiring and protruding board front wiring as well as standard 35mm rail type terminal block wiring, which is convenient for on-site installation and has strong versatility.

4 Technical conditions

4.1 Environmental reference conditions

Environment temperature: 20±2℃

Relative humidity: 45%～75%

Atmospheric pressure: 86～106Kpa

4.2 Normal use conditions

Ambient temperature: -10℃～+50℃

Relative humidity of environment: not more than 90%

Atmospheric pressure: 80～110KPa

Limit temperature during storage and transportation: -25℃～+70℃

The altitude of the place of use: no more than 2500 meters

The surrounding medium in the use environment has no explosion hazard; it does not contain corrosive gas; the concentration of conductive dust contained should not reduce the insulation level below the allowable limit value.

4.3 Rated parameters

Rated AC voltage: 100V; 100/3 V; 220V; 380V

Rated AC current: 1A; 5A

Rated frequency: 50HZ; 60HZ

Auxiliary power supply rated voltage: 220VDC; 110VDC; 48VDC; 380VAC; 220VAC, allowable voltage fluctuation range: 0.8 to 1.15 times the rated voltage.

4.4 Characteristic parameters

4.5 Maximum power consumption:

AC voltage circuit: no more than 0.5VA per phase at 100V

AC current loop: no more than 0.5VA per phase under 5A; no more than 0.2VA per phase under 1A

Auxiliary power supply: not more than 6W at 220VDC; not more than 10VA at 220VAC

4.6 Maximum capacity of contacts:

Cut-off load capacity: DC 250V or less, τ=5ms, inductive load 50W, resistive load 150W;

AC below 250V, load 1200VA;

Allow long-term connection current: 5A.

4.7 AC circuit overload capacity:

AC voltage circuit: continuous work under 1.2 times the rated voltage

AC current loop: continuous work under 2 times the rated current;

It can work for 10S under 10 times of rated current;

It can work for 1S under 40 times the rated current.

4.8 Insulation resistance: Use an open-circuit voltage 500V megger to measure the insulation resistance between the exposed non-charged metal parts or shells of the relays connected to each conductive terminal and should not be less than 10MΩ.

4.9 Insulation withstand voltage: each lead-out terminal to the housing locking screw can withstand a power frequency voltage of 2000V, and the same group of contacts can withstand a power frequency voltage of 1000V, which lasts for one minute without breakdown.

4.10 Anti-interference performance: meet the national GB6162-85 "Electrical Interference Test of Static Relays and Protection Devices" standard.

4.11 Electrical life: In the DC250V circuit, cut off the current τ=5ms, 50W, more than 104 times.

4.12 Mechanical life: The contact is 3 million times in no-load state.

5 Structure type (see the relay structure size diagram for details)

5.1 The rear wiring structure of the embedded board AK11, AP11 and the rear-view wiring diagram of the protruding board front wiring AQ11 (subject to the company's product samples)

5.2 JK-1/8 structure rear view wiring diagram (subject to company product samples)

5.3 DZ-1 structure terminal block type terminal wiring diagram (subject to company product samples)

6 Use

6.1 Before energizing the relay, confirm whether the voltage level of the connected relay is consistent with the actual parameters, otherwise the relay may be damaged; check whether the relay is damaged during transportation and storage, and the relay screw fasteners should not be loose; if there are damaged parts , Please contact us to replace it for you.

6.2 Use the dial switch to set the action value according to the formula on the relay panel.

Zero sequence overvoltage relay setting formula: U=K*[10*□+□+10] V; K value depends on the setting range

When the voltage range is 10～109V, K=1 U=[10*□+□+10] V;

When the voltage range is 20～218V, K=2 U=2*[10*□+□+10] V

Zero sequence overcurrent relay setting formula: I=K*[□+0.1*□+1]A; K value depends on the setting range

When the current range is 1～10.9A, K=1 I=[□+0.1*□+1]A;

When the current range is 2～21.8A, K=2 I=2* [□+0.1*□+1]A;

When the current range is 5～54.5A, K= U=5*[□+0.1*□+1]A

7 Ordering instructions

When ordering, please specify the relay model, specification, quantity, auxiliary power supply, AC rated voltage or current of the coil, structure and other requirements.