size-1 error in dispatchable load

[pramu...@gmail.com]

Dear Pypower user,

I tried to create a system based on IEEE14 bus system with several dispatchable load. I model the dispatchable load with represent it to generator with negative value of PG and QG. However, when I run the runopf,

there is error occurred."only size-1 arrays can be converted to Python scalars"

The same values works fine in Matpower, but it gives error in Pypower. When I change the value in to 0 or positive value, there is no error.

Can anybody give me a solution? The .py file is attached

Best regards,

Pramudya