600V High voltage limitation circuit.

I need a circuit design & fabrication of a prototype unit to limit and dissipate high voltage spikes on a 600 VDC, 3.5 kW power system. A small wind turbine on my farm produces up to 3.5 kW, 600 VAC,3 phase power at wild AC frequency (0 to 200 Hz?). A full bridge, 3 phase rectifier takes the wind turbine output & generates 0 to 600 VDC, single phase, single leg, at varying amps, with some noise. If the rectifier output voltage exceeds 300, 400, or 500 VDC (switch selectable), the rectifier engages a load dump heater to dissipate excess power and control maximum voltage output. The rectifier's DC output is fed to a Morningstar Tristar MPPT Charge controller (Model: TS-MPPT-60-600V-48) so as to charge a 48 VDC battery bank. This $2,000.00 Tristar is extremely sensitive to voltage spikes above 600 Volts (AC &/or DC ?), and will be destroyed by transients, flyback, resonating, transient spikes, or similar. I am told the Tristar internally contains TVS components on its input lines, and possibly elsewhere. Nuclear high altitude EMP events produce up to 200 kV/meter electric fields with rise times of 5 nanoseconds, and there are COTS (Commercial Off-the-Shelf) solutions for dissipating and protecting against these free-air induced voltage spikes (NB: USA & NATO MIL-Spec is only 50 kV/m), so there is hope for me too via your expert design. If you know of a currently existing COTS solution, that knowledge is valuable to me. Your design should assume that the Tristar must not see any voltages in excess of 525 Volts under any foreseeable circumstances, giving a 75 V safety margin (ie. 525 VDC safe max., to 600 VDC danger catastrophic destruction limit). Assume the bridge rectifier will operate at a nominal 300 VDC, with the dump heaters on PWM between 300 and 400, and fully on at 400 VDC, or higher. Therefore, your design device will normally operate in the 400 to 525 VDC range, and will passively monitor voltages at voltages lower than 400 volts.. There are 10 amp fuses on the 3 phase AC side. There are COTS surge arrestors (Delta and Midnite Sun) already installed on the system's AC, rectified 600 VDC, and the 48 VBC battery side as protection against lightning strikes. I got one solution, but need to prove the circuit and do some theoretical calculation. Please contact me if you have rich experience in this field.