Portable cable AC voltage withstand test device? Wuhan UHV specializes in producing series resonant devices, with a wide range of product selection and professional electrical testing. When looking for series resonant devices, choose Wuhan UHV.
Wuhan UHV, a leading manufacturer of portable cable AC voltage withstand test devices (also known as cable AC voltage withstand test devices), is one of the few series resonance test device manufacturers that has passed the type test certification of the national authoritative testing institution, the Electric Power Industry Electrical Equipment Quality Inspection and Testing Center (Wuhan High Voltage Research Institute). It is a partner of State Grid Corporation of China, Southern Power Grid Corporation, the five major power generation groups, China Electric Power Research Institute, State Grid Electric Power Research Institute, provincial electric power research institutes, power supply companies in various cities, as well as well-known customers such as China Petroleum, Sinopec, Aluminum Industry Corporation of China, China Energy Construction, China Railway, CRRC, Shougang, Baosteel, and Wuhan Iron and Steel. It is a top three brand in the series resonance test device industry!
The AC withstand voltage test of various large power transformers, power cables, steam turbines, hydro generators, and other capacitive equipment must be strictly conducted regularly in accordance with the test regulations. Under power frequency conditions, due to the large capacitance of the test object or high requirements for the test voltage, there are also high requirements for the power capacity of the test device. Traditional power frequency withstand voltage devices often have large individual volumes, heavy weights, are not easy to transport on site, and are not easy to combine arbitrarily, resulting in poor flexibility. At present, a better method is to use series resonance for voltage withstand testing.
Working principle of portable cable AC voltage withstand test device
The series resonance composed of reactor L and the tested capacitor C has a fixed resonance frequency F=1/(2 π√ L · C). When the test frequency is equal to this frequency, the circuit resonates. Through this principle, power is provided by a frequency modulation power supply to the excitation transformer, which is then transformed into medium voltage by the excitation transformer and added to L and the tested capacitor C. By changing the output frequency of the frequency modulation power supply, the circuit is in series resonance state, and then adjusting the output voltage of the frequency modulation power supply to achieve the required voltage value on the test sample.
Composition of a complete set of portable cable AC voltage withstand test device
Frequency modulation power supply - can change both its output frequency and output voltage.
Excitation transformer - plays a role in coupling signals and voltage conversion, and increases voltage according to its own changes.
Reactor - connected in series with the test sample to form an LC series resonant circuit.
Capacitive voltage divider - measures the voltage on the test sample and feeds it back as a sampling signal to the frequency modulation power supply.
Compensation capacitor - compensates for small capacitance of the test sample and adjusts the frequency of the test sample.
The portable cable withstand voltage test device adopts the method of adjusting the frequency of the power supply to achieve resonance between the reactor and the tested capacitor, obtaining high voltage and high current on the tested object. It is a new method and trend of high voltage testing, which has been widely used at home and abroad. The portable cable withstand voltage test device adopts a dedicated SPWM digital waveform generation chip with a frequency resolution of 16 bits, and the frequency fineness can reach 0.1Hz at 20-300Hz. It adopts orthogonal asynchronous fixed carrier modulation method to ensure good output waveform in the entire frequency range; The power section adopts advanced IPM modules to ensure instrument stability and safety with minimal weight.