Supply of single-chip relay protection tester

Introduction

On the basis of referring to the "Technical Conditions for Microcomputer Relay Protection Test Equipment (Discussion Draft)" issued by the Ministry of Electric Power, extensively listening to user opinions, summarizing the advantages and disadvantages of similar products in China, and fully utilizing modern microelectronics technology and devices, a new type of miniaturized microcomputer relay protection tester is developed. The microcomputer relay protection tester adopts a single machine independent operation and can also be connected to a laptop for operation. The host is equipped with a new generation high-speed digital signal processor microcomputer, a true 16 bit DAC module, a new modular high fidelity high-power amplifier, a large screen LCD display, and a flexible and convenient rotating mouse controller. Single machine independent operation already has strong functionality and can perform most experiments, while connecting to a computer for operation has even greater operational capabilities. Small size and high precision. It has the performance and functions of a large testing instrument, as well as the advantages of a small and flexible testing instrument, easy operation, and high reliability, with a high cost performance ratio. It is a handy tool for relay protection workers.

working principle

The relay protection testing instrument is divided into two circuits: the main circuit and the auxiliary circuit. The main circuit is adjusted with a large knob, and the auxiliary circuit is adjusted with a small knob. The main circuit is controlled by the "output selection" button switch on the panel to output various quantities, and the digital voltage/current meter on the instrument can automatically monitor its output value while switching each output. The auxiliary circuit is controlled by an output switch to directly adjust the output, and can be measured with an external multimeter.

Main circuit principle of relay protection testing instrument

The input AC220V power supply enters the input terminal of the dual carbon brush voltage regulator T1 through the output control relay K1 via the fuse. The electricity adjusted by the large knob of T1 enters the isolation transformer T2 (part-time current collector). The current collector is divided into three taps for output, one tap is AC0-250V output, with a rated current of 3A; the output voltage of this tap can output 0-350V DC voltage after rectification and filtering; The second tap is 15V (10A), which outputs 0-10A AC current through a sensor controlled by a relay, 0-500mA AC current through a resistor, and 0-10A or 0-500mA DC current through a relay conversion; The third tap is the 10V (100A) high current terminal, which directly outputs 100A current through the primary side of the sensor. This circuit has strong load capacity, but the output is slightly overloaded and cannot be in a high current state for a long time. Thermal relay calibrator

Auxiliary circuit of relay protection testing instrument

The auxiliary circuit of the relay protection testing instrument is the same as the main circuit. The AC220V power supply enters the double carbon brush voltage regulator T1 through the fuse to adjust the voltage. The output voltage can be directly adjusted to 0-20V or 0-250V AC voltage or 0-350V DC voltage through the isolation transformer T4. The rated current of this circuit is 1A. Press the "output control" switch of the auxiliary circuit and adjust the small knob to output.

measurement circuit

The main circuit output adjusted by the large knob is AC "0-250V", "0-500mA", "0-10A", "0-100A", and DC "0-350V", "0-500mA", and "0-10A", which are converted by relays on the device's circuit board. With each gear switch, the corresponding output can be monitored. The range of "0-500mA" is included in the range of "0-10A". When in use, monitoring from "0-10A" is equivalent to monitoring from "0-500mA".

time measurement

The device is equipped with a 6-digit stopwatch, which can be started internally or externally. When starting internally, press the "output control" switch to start the stopwatch. Short circuit the stopwatch terminal on the device panel through the contact to stop the stopwatch. The stopwatch is equipped with a separate power switch, which can be turned off when not in use.

audio-visual prompt

The circuit equipment is equipped with a built-in sound and light prompt circuit. When the contact of the tested circuit breaker is activated, the contact can be connected to the sound and light prompt socket of the test box. The test box will emit an alarm sound or light to indicate the action of the circuit breaker contact.

Supply of single-chip relay protection tester

rated parameters

AC current output

Output accuracy relay protection tester: Level 0.5

Phase current output (effective value) 0-40A

Triple current output (effective value) 0-120A

Long term allowable operating value (effective value) of phase current 10A

Maximum output power of phase current 420VA

Maximum output power of 900VA at maximum output of triple current

Allowable working time of 10 seconds when the maximum output of the triple current is achieved

Frequency range (fundamental) 20-1000Hz

Harmonic order 1-20 times

DC current output

Output accuracy level 0.5

Current output: 0~± 10A per phase, 0~± 30A per triple junction

Maximum output load voltage 20V

AC voltage output

Output accuracy relay protection tester: Level 0.5

Phase voltage output (effective value) 0-120V

Line voltage output (effective value) 0-240V

Phase voltage/line voltage output power 80VA/100VA

Frequency range (fundamental) 20-1000Hz

Harmonic order 1-20 times

DC voltage output

Output accuracy level 0.5

Phase voltage output amplitude 0~± 160V

Line voltage output amplitude 0~± 320V

Phase voltage/line voltage output power 70VA/140VA

Measurement of switch quantity and time