Overlay harmonic test program function
The currents and voltages of each phase can be arbitrarily superimposed with the DC component and 2 to 9th harmonic components on the fundamental wave. The initial angle of the superposition can be set arbitrarily. Each component and the fundamental wave parameters can be manually adjusted arbitrarily, or after selecting a certain variable, the variable will automatically change within the set range of steps according to the set step size. During the entire output process, the waveforms of the current and voltage outputs are displayed online, and the peak values and initial superposition phase angles of the fundamental wave, DC component, and each harmonic are also displayed. At the same time, the total effective value, harmonic content, and harmonic distortion rate of each phase current and voltage are automatically calculated.
Parameter settings
1. Once you enter the main interface of this program, the left upper part of the interface is the parameter setting area for phase A voltage. Through the control column in the middle of the interface, you can activate the parameter setting areas for the voltages and currents of other phases. The right upper part of the interface shows the combined waveform diagrams of the currents and voltages of each phase, and the two icons of Vp-p and Ipp control the enlargement or reduction of the waveforms. At the top of each phase parameter setting area, the total effective value, harmonic content and harmonic distortion rate of the current and voltage of this phase are displayed.
2. In each parameter setting area, the amplitudes of the fundamental wave and each harmonic are represented by peak-to-peak values, the amplitude of the DC component is expressed by the average root value, and the initial angle of the harmonic is its superimposed initial angle, with the fundamental phase angle as the reference. The initial angle and phase value range: 0 – 359 degrees. The amplitude range: for the DC component, it is 100% of the fundamental peak value. For other components, voltage: 0 – 169.7V, current: 0 – 56.56A.
Variable selection: Three-phase voltage or current of A, B, and C can be selected. Variable selection 2: The DC component, fundamental wave, or the peak or initial phase angle of 2-9 harmonics corresponding to “Variable selection 1″ can be selected. Variable start value: The initial value of the variable output under the automatic change mode. Variable end value: The end value of the variable change range under the automatic change mode.
Variable change step size: In the automatic change mode, the step size of the variable’s change per step. The value ranges of these three variables depend on “Variable Selection 1″ and “Variable Selection 2″. It is the same as the setting range of each phase current, voltage peak or initial phase angle in the main interface.
Variable variation range: There are two options: “Start – End” and “Start – One – End Start”. “Start – One – End” indicates that the variable changes from the initial value to the terminal value in steps, and during this period, if a protection or relay action signal is received, the change stops, the test ends, and the value of the variable at that time is recorded as the action value, and the action time is also recorded. “Start – One – End Start” means that the variable changes from the initial value to the terminal value. During this period, if a protection or relay action signal is received, the action value is recorded but the output does not stop. Instead, the direction of change is immediately changed to change in the direction of the initial value in steps until a return signal is received. At this time, the value of the variable is recorded as the return value, and the return time is also recorded, and the output stops, and the test ends. If no action signal is received during this period, the test stops at the terminal value. The change of the variation direction is made. If no return signal is received after changing the direction, the test stops when the variable returns to the initial value. The variable variation mode is divided into automatic variation and key press variation.
Automatic adjustment mode: According to the above control parameters, control the output of the selected variable. Button change mode: The above control parameters (except for the variable parameters) are meaningless. After output, the current and voltage values of each phase currently set are output first. Then, use the cursor keys to move the cursor, and use the keys 1, 2, 3 or q, w, e to adjust the values in the column where the cursor is located. When the relay operates or returns, record the current value of the variable at that time as the operating value or return value. You can also close the input signal channel. When the relay operates or returns, press the “D” or “C” key to manually record the operating value or return value. Input contact function: In the manual button change mode, it can be set to be off, and manually record the operation and return values.
3. When setting the parameters or during output, if the combined value of a certain current or voltage exceeds the range that the relay protection testing instrument can output, an information indicating parameter exceeding the limit will be displayed. Press any key and the system will automatically take the critical value of the range. In the automatic change mode, if the limit information appears, you can also cancel the test by pressing the ESC key or the right mouse button.
Testing method
After setting the parameters, connecting the test lines and signal lines, press the F10 key or click on the “Start Test” area with the mouse to start the output. If the selected variable does not correspond to the currently activated parameter settings area, the corresponding parameter settings area for the selected variable will be automatically activated first. Then, press the F10 key or click on the “Start Test” area again to start the test.
Under the key change mode, after the output starts, the parameter setting area for any one phase of current and voltage can be activated using the mouse or keys, allowing for the arbitrary adjustment of the component values of the voltage and current of any phase. After the test is completed, press the F10 or ESC key or click the “Stop Test” area with the mouse to stop the output and end the test. If it is the automatic change mode, the variables will change automatically, while non-variables will output according to the set values. During the output process, you can also press the F10 or ESC key or right-click to cancel this test halfway.
In this program, if the output value of any phase current exceeds 10A, the program sets a maximum output duration. Once this duration is exceeded, the program will automatically shut off the output.
Post time: Apr-02-2026