The composition and main features of the oscilloscope dynamic electric energy test system
Electric energy measurement is a mature, commonly used and important testing technology. It is closely related to major issues such as energy utilization, economic benefits and environmental protection. However, the test object of what is usually referred to as "electrical energy measurement" is generally DC or power frequency electrical energy. They all behave as steady-state signals. Its value does not change with time or changes slowly or periodically. Generally speaking, various electric energy measuring instruments can be used to measure certain parameter values according to industrial standards. However, with the development of scientific applications and modern industrial automation technology, in many experimental studies, industrial processes and product tests, energy changes are no longer a steady-state process, but appear as sudden, random and instantaneous changes over time. is a typical dynamic time domain process. There are many such examples in practice. For example, in the automated control of industrial processes, the operating conditions of motors are becoming increasingly complex, which is manifested by a large increase in the transition processes of motor operation. That is, in order to execute the control program instructions, the motor must frequently start, stop, change speed, reverse direction, load, unload, etc. Another example is the filling and release of energy in energy storage devices (capacitors, inductors, batteries, etc.), which often appear as a single transient time domain process. Another typical example is the ignition energy of a gasoline engine, which is a time-domain process with a small duty cycle, a very steep pulse edge, and strong electromagnetic interference. Although the testing theory of steady-state energy and dynamic energy is the same, the voltage and current are multiplied at the corresponding time to obtain the power and then integrated over time, the difficulty of the testing technology and the complexity of the equipment are quite different. The latter requires the test system to have sufficient bandwidth, good dynamic response and strong anti-interference ability. At the same time, the captured information must be stored in time, and then analyzed, processed, and obtained as time domain waveforms of voltage, current, power, and energy, not just parameter values at certain moments. To achieve the above test tasks, there are currently no ready-made dynamic energy test equipment to choose from, and you need to construct your own test system. Among various methods, the preferred solution is: voltage and current probe + desktop smart oscilloscope + computer + application test program. Among them, the correct selection of oscilloscope is a key factor.
Test system composition and main features
The dynamic energy testing system based on TDS1000/2000/3000B series oscilloscopes mainly consists of voltage and current probes, TDS series oscilloscopes, application test software, computers and peripheral equipment.
Now take the gasoline engine ignition energy test as an example to illustrate the working process of the test system: first, the high-voltage probe attenuates the pulse high voltage output by the ignition device and then sends it to a Y input channel of the TDS series oscilloscope, while the current probe attenuates the pulse output from the ignition device. The small current is converted into a corresponding small pulse voltage and input to another Y input channel of the TDS series oscilloscope. Then adjust various working status parameters of the oscilloscope, capture the voltage and current time domain waveforms in a timely and correct manner, and store them in the corresponding reference memory. Finally, with the help of application testing software, the data captured by the oscilloscope is transmitted to the computer and processed to obtain energy-related data tables and time domain waveform diagrams. If necessary, the required information is output in hard copy or transmitted over the network.
