61results about How to "Intuitive and accurate test results" patented technology

The invention relates to a control circuit for detecting pavement disease by sound effect radar and ground penetrating radar and a detector comprising the control circuit. The sound effect radar and the ground penetrating radar are jointly used for detecting the pavement disease, so that the thickness, the compressive modulus of elasticity and the defect of each structural layer can be accurately confirmed. A sound wave shock excitation device and the ground penetrating radar control signals to be synchronized via the controller, the thickness of the structural layer of each road is accurately measured by virtue of the electromagnetic wave, and the compressive modulus of elasticity of each structural layer is computed by the sound wave propagation velocity difference. The control circuit and the detector are high in automaticity, low in fault efficiency, small in volume and convenient to use. Compared with the conventional pavement structure detector, the detector can realize quantized non-destructive detection on the thickness of the structural layer, the compressive modulus of elasticity, the structural discontinuous invisible disease and the like, and the detecting speed per hour can reach more than 60km / h, therefore, the detector is wide in application prospect.

A power-grid-impact-free detection method for the low voltage ride through function of a doubly-fed wind turbine generator system is characterized in that the stator side of the doubly-fed wind turbine generator system and a power grid are in the off state all the time when the low voltage ride through function of the doubly-fed wind turbine generator system is detected through the detection method, power grid faults of different types and different voltage drop depths are simulated by inputting a reactor with the adjustable resistance value, and the output waveforms of a converter of the doubly-fed wind turbine generator system and all physical quantities of an electric generator are detected so that whether the doubly-fed wind turbine generator system has the low voltage ride through function meeting the requirement of the national standard or not can be judged. By means of the detection method, whether the doubly-fed wind turbine generator system has the low voltage ride through function or not can be effectively verified, the performance index of the low voltage ride through of the doubly-fed wind turbine generator system can be rapidly obtained, no impact on the power grid is caused in the detection process, the detection method is simple and feasible, the detection result is visual and accurate, the detection cost is low, and the detection method is particularly suitable for the field of the wind power plant online detection of the low voltage ride through function of the doubly-fed wind turbine generator system.