Returns a list of 2-tuples, e.g. [(-3.14, 3.14), (-0.001, 0.001)],
        one tuple per parameter, giving min and max for that parameter.

def getSensorLimits(self):
        """ Returns a list of 2-tuples, e.g. [(-3.14, 3.14), (-0.001, 0.001)],
        one tuple per parameter, giving min and max for that parameter.
        """
        limits = []
        for i in range(len([b for b in self.env.case.buses if b.type == PQ])):
            limits.append((0.0, self.env._Pd0[i]))

        logger.info("Sensor limits: %s" % limits)

        return limits