You show what looks like a three-phase circuit breaker. Is that the actual circuit breaker feeding your residence? Odd.
Are you in a location where you can discuss your needs with a well-qualified electrical supply house? If so ask if they can supply a main circuit breaker compatible with your main service panel and having an auxiliary voltage activated trip coil or “dump” coil. Such a dump coil provides for tripping the main breaker off by means of an externally applied, low current, trip voltage. Such a breaker would allow you to shut off power to your residence within a few milliseconds of a damaging voltage arriving at your main panel.
See the discussion of this type of breaker under the heading, “Dual Coil with Remote Shutdown” in http://www.carlingtech.com/circuit-protection-circuit#4
Tripping the main breaker would require that a device be built or purchased that could detect the presence of an overvoltage condition and generate the required trip voltage. This would probably require a semiconductor circuit, since an “overvoltage relay” would possibly have too much delay to provide adequate protection from an instantaneously applied overvoltage. Such a detector delay would add to the inherent delay in tripping the main breaker, thus increasing the liklihood of damage to your appliances. You may also be well advised to provide a “whole house” varistor surge protector to clip the peak overvoltage that could pass into your home while waiting for your main breaker to trip.
A tricky part of this approach is providing adequate protection while minimizing annoying nuisance trips due to common transient voltage peaks coming in on the line or generated within your home by appliances. A survey of line quality would be very useful but is probably not feasible to obtain. I understand that some utilities here in the US will survey line voltage using automated instruments left in place for a day or two upon request.
Of course, this approach would leave you sitting in the dark after an overvoltage condition. However, that may be better than replacing a house full of appliances.
Let us know if this approach is appealing to you and whether you can obtain an appropriate breaker with auxiliary trip coil. If so, we can probably help design or locate an appropriate overvoltage sensing circuit. This approach would be far cheaper than any devices that would actually condition incoming excessive voltages and allow you to continue normal activities as if nothing out of the ordinary was happening.