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Digital-analog Integrated & Ultra-light and Thin | Application of the New-generation Handheld Relay Protection Tester in a 500kV Newly-built Substation

Release Date: August 10, 2022   Wuhan Haomai Electric Power Automation Co., Ltd.

Recently, Wuhan Haomai was invited by an extra-high voltage company to participate in the relay protection test project for the maintenance of a 500kV newly-built substation. Considering the cramped on-site test environment, the maintenance personnel chose the Relaystar-Z70 Handheld Digital-analog Integrated Relay Protection Tester—a portable device with analog quantity output function—to complete this test task. The tester is equipped with a large-capacity lithium battery, supports the output of 3-channel voltage and 3-channel current for analog quantities, and is configured with 2 groups of input contacts and 2 groups of fast output contacts, which fully meets the on-site commissioning requirements.

△ Relaystar-Z70 Handheld Digital-analog Integrated Relay Protection Tester

Developed specifically for rapid troubleshooting in power systems, the Relaystar-Z70 reduces the overall size to approximately A4 paper dimensions and the weight to around 2kg on the premise of maintaining high precision and stable amplitude output, enabling easy one-handed operation. It supports both analog and digital quantity output. The built-in general test module can perform conventional current and voltage injection tests, while the professional relay protection test module can verify and commission the performance and functions of various protection devices, including transformer protection, line protection, generator-transformer unit protection, and electric railway differential protection. It is applicable to secondary system protection commissioning, control circuit troubleshooting, and smart substation optical link troubleshooting.

Test Item: Verification of Reclosing Operation Time for Line Protection 

Test Equipment: Relaystar-Z70 Handheld Digital-analog Integrated Relay Protection Tester

Test Procedures

1. Insert the cables into the voltage and current terminals on the top of the Relaystar-Z70 according to the markings, and connect the other ends to the voltage and current acquisition terminal blocks of the protection device.

2. Switch the Relaystar-Z70 to the analog quantity output interface, open the state sequence interface to set the test parameters, and select three states:

State 1: Set the rated voltage to 57.735V and the current to 0A; select key trigger as the trigger mode.

State 2: Set the fault state, select the fault phase through short-circuit calculation, set the fault current and fault duration; select time trigger as the trigger mode.

State 3: Set the reclosing state, set the voltage to 57.735V and the current to 0A; select time trigger as the trigger mode.

3. Click to start the test. State 1 eliminates the alarm information of the protection device, and the reclosing function displays "Charging Completed". At this point, click the switch button on the Relaystar-Z70 to switch to the fault state, which will then automatically switch to the reclosing state according to the set time. Check the reclosing operation message information on the protection device.

During the entire test process, the Relaystar-Z70 was powered by its lithium battery without the need for an external power supply, featuring stable output and a precision of up to 0.1%. With a user-friendly software interface, one-handed grip design for easy mobility, and smooth full-touch screen operation, coupled with a rich set of test modules, it successfully completed the on-site commissioning task and won unanimous praise from the user unit.