Excitation technology plays an important part in the field of electromagnetic flowmeter (EMF). The form of the magnetic field directly determines the characteristics of the flow signal. No breakthrough has been made on the excitation technology since the invention of sinusoidal wave excitation, rectangular wave excitation, and double-frequency excitation. In this paper, firstly a new three-value trapezoidal wave excitation with transient responses is proposed. Then the signal model is established, and the verification experiments are carried out. Finally, flow calibration experiments and comparative experiments on the trapezoidal wave excitation are conducted on the experimental platform. The experiment results show that the electromotive force output by the EMF based on three-value trapezoidal wave excitation is linearly related to the flow velocity. When the flow velocity is 0.257 m/s, the relative error is only 1.635%. When the flow velocity reaches 2.133 m/s, the relative error is reduced to 0.432%. The three-value trapezoidal wave excitation with the transient analysis satisfies the requirements of the EMF with high accuracy. The research also shows that the excitation frequency has a great influence on the measurement accuracy of the EMF based on three-value trapezoidal wave excitation.

励磁技术在电磁流量计（EMF）领域中起着重要的作用。磁场的形式直接决定流量信号的特性。自从正弦波激励，矩形波激励和双频激励发明以来，激励技术没有取得突破。本文首先提出了一种新的具有瞬态响应的三值梯形波激励。然后建立信号模型，并进行验证实验。最后，在实验平台上进行了流量校准实验和梯形波激励的对比实验。实验结果表明，基于三值梯形波激励的电动势输出的电动势与流速呈线性关系。当流速为0.257 m / s时，相对误差仅为1.635％。当流速达到2.133 m / s时，相对误差减小到0.432％。具有瞬态分析的三值梯形波激励满足了EMF的高精度要求。研究还表明，基于三值梯形波激励，激励频率对电磁场的测量精度有很大影响。具有瞬态分析的三值梯形波激励满足了EMF的高精度要求。研究还表明，基于三值梯形波激励，激励频率对电磁场的测量精度有很大影响。具有瞬态分析的三值梯形波激励满足了EMF的高精度要求。研究还表明，基于三值梯形波激励，激励频率对电磁场的测量精度有很大影响。