Temperature control method based on symbol identification in cable current-carrying capacity heat cycling test

Abstract

The invention relates to a temperature control method based on symbol identification in a cable current-carrying capacity heat cycling test, symbol value computing is carried out on the acquired temperature and current, the symbol value which reflects the current temperature control state is obtained, the target parameters are upgraded after the symbol value judgment, a voltage regulator motor is controlled to rotate positively and negatively, the temperature rising and reducing control is realized, after the temperature reaches the set state, the symbol values of temperature and current signals are repeatedly extracted, the motor is controlled again to operate, and accordingly, the quick stable temperature control process is realized. By the temperature control method, the temperature of a cable conductor in the cable current-carrying capacity heat cycling test is quickly stabilized at the set value, the temperature control process has better robustness, the temperature overshoot and oscillation are suppressed, the whole control process is simple to realize, has less calculations and exact control logic, and can be widely applied to the conductor temperature control or the constant value control of variable parameters with the similar requirements.

Description

technical field [0001] The invention relates to a power cable testing technology, in particular to a temperature control method based on sign discrimination in a cable ampacity cycle heating test. Background technique [0002] In the power cable test, the current-carrying capacity-temperature relationship of the cable directly reflects the working characteristics of the cable and the actual allowable current-carrying capacity. According to the IEC60364 standard of the International Electrotechnical Commission, the cable whose insulator material is polyvinyl chloride (PVC) has a conductor temperature limit of 70°C; the conductor temperature limit of cross-linked polyethylene (XPLE) and ethylene-propylene composite paste (EPR) cables is 90°C ℃; for bare cables that are not close to minerals, the conductor temperature is limited to 105 ℃. Carrying out rapid ampacity cycle heating tests for different types of cables, reaching the allowable upper temperature limit of the cables ...

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