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Your understanding of power is incorrect. Energy is stored inside a moving mass, not power. Power is energy divided by time. So, you can de-accelerate either quickly (high power) or slowly (low power).

Let's take a simple example: a 1920ies streetcar. One of the most simple arrangements driving electrical. It has a series DC motor and some resistors on the roof top for braking.

Let's say we have an energy of 50kWs stored in the moving mass of the car. The resistive brakes can take up to 10kW without overheating. So, using the electrical brake at full power, we should be able to bring the car to standstill in five seconds. Okay, but: can we employ that?

Mechanical power is torque times drive speed

$$P \sim M \cdot n$$

but what is the torque/speed relation? Luckily, the drive of such a 1920ies streetcar has a torque/speed characteristic which is roughly a hyperbolic curve.

$$M \sim \frac{1}{n}$$

Torque is very high at low speeds and low at higher speeds. This is very practical for both accelerating and braking. So, the power we can brake at is

$$P \sim \frac{1}{n} \cdot n = 1$$

So, yes: we can brake the streetcar with constant power, while the torque is the inverse of the momentary drive speed. And that's true for any power. The only thing we do by changing the braking resistance is scaling the de-acceleration curve.

For another drive, you had to look at the M/n characteristic first, then deduce the power to speed relation from that. But this curve is very common for vehicles because it's so favourable, making it possible to make full use of the power rating of the equipment at all speeds.

Your understanding of power is incorrect. Energy is stored inside a moving mass, not power. Power is energy divided by time. So, you can de-accelerate either quickly (high power) or slowly (low power).

Let's take a simple example: a 1920ies streetcar. One of the most simple arrangements driving electrical. It has a series DC motor and some resistors on the roof top for braking.

Let's say we have an energy of 50kWs stored in the moving mass of the car. The resistive brakes can take up to 10kW without overheating. So, using the electrical brake at full power, we should be able to bring the car to standstill in five seconds. Okay, but: can we employ that?

Mechanical power is torque times drive speed

$$P \sim M \cdot n$$

but what is the torque/speed relation? Luckily, the drive of such a 1920ies streetcar has a torque/speed characteristic which is roughly a hyperbolic curve.

$$M \sim \frac{1}{n}$$

Torque is very high at low speeds and low at higher speeds. This is very practical for both accelerating and braking. So, the power we can brake at is

$$P \sim \frac{1}{n} \cdot n = 1$$

So, yes: we can brake the streetcar with constant power, while the torque is the inverse of the momentary drive speed. And that's true for any power. The only thing we do by changing the braking resistance is scaling the de-acceleration curve.

For another drive, you had to look at the M/n characteristic first, then deduce the power to speed relation from that. But this curve is very common for electrical vehicles because it's so favourable, making it possible to make full use of the power rating of the equipment at all speeds.

Your understanding of power is incorrect. Energy is stored inside a moving mass, not power. Power is energy divided by time. So, you can de-accelerate either quickly (high power) or slowly (low power).

Let's take a simple example: a 1920ies streetcar. One of the most simple arrangements driving electrical. It has a series DC motor and some resistors on the roof top for braking.

Let's say we have an energy of 50kWs stored in the moving mass of the car. The resistive breaks can take up to 10kW without overheating. So, using the electrical brake at full power, we should be able to bring the car to standstill in five seconds. Okay, but: can we employ that?

Mechanical power is torque times drive speed

$$P \sim M \cdot n$$

but what is the torque/speed relation? Luckily, the drive of such a 1920ies streetcar has a torque/speed characteristic which is roughly a hyperbolic curve.

$$M \sim \frac{1}{n}$$

Torque is very high at low speeds and low at higher speeds. This is very practical for both accelerating and braking. So, the power we can break at is

$$P \sim \frac{1}{n} \cdot n = 1$$

So, yes: we can brake the streetcar with constant power, while the torque is the inverse of the momentary drive speed. And that's true for any power. The only thing we do by changing the braking resistance is scaling the de-acceleration curve.

For another drive, you had to look at the M/n characteristic first, then deduce the power to speed relation from that. But this curve is very common for vehicles because it's so favourable, making it possible to make full use of the power rating of the equipment at all speeds.

Your understanding of power is incorrect. Energy is stored inside a moving mass, not power. Power is energy divided by time. So, you can de-accelerate either quickly (high power) or slowly (low power).

Let's take a simple example: a 1920ies streetcar. One of the most simple arrangements driving electrical. It has a series DC motor and some resistors on the roof top for braking.

Let's say we have an energy of 50kWs stored in the moving mass of the car. The resistive brakes can take up to 10kW without overheating. So, using the electrical brake at full power, we should be able to bring the car to standstill in five seconds. Okay, but: can we employ that?

Mechanical power is torque times drive speed

$$P \sim M \cdot n$$

but what is the torque/speed relation? Luckily, the drive of such a 1920ies streetcar has a torque/speed characteristic which is roughly a hyperbolic curve.

$$M \sim \frac{1}{n}$$

Torque is very high at low speeds and low at higher speeds. This is very practical for both accelerating and braking. So, the power we can brake at is

$$P \sim \frac{1}{n} \cdot n = 1$$

So, yes: we can brake the streetcar with constant power, while the torque is the inverse of the momentary drive speed. And that's true for any power. The only thing we do by changing the braking resistance is scaling the de-acceleration curve.

For another drive, you had to look at the M/n characteristic first, then deduce the power to speed relation from that. But this curve is very common for vehicles because it's so favourable, making it possible to make full use of the power rating of the equipment at all speeds.

Your understanding of power is incorrect. Energy is stored inside a moving mass, not power. Power is energy divided by time. So, you can de-accelerate either quickly (high power) or slowly (low power).

Let's take a simple example: a 1920ies streetcar. One of the most simple arrangements driving electrical. It has a series DC motor and some resistors on the roof top for braking.

Let's say we have an energy of 50kWs stored in the moving mass of the car. The resistive breaks can take up to 10kW without overheating. So, using the electrical brake at full power, we should be able to bring the car to standstill in five seconds. Okay, but: can we employ that?

Mechanical power is torque times drive speed

$$P \sim M \cdot n$$

but what is the torque/speed relation? Luckily, the drive of such a 1920ies streetcar has a torque/speed characteristic which is roughly a hyperbolic curve.

$$M \sim \frac{1}{n}$$

Torque is very high at low speeds and low at higher speeds. This is very practical for both accelerating and braking. So, the power we can break at is

$$P \sim \frac{1}{n} \cdot n = 1$$

So, yes: we can brake the streetcar with constant power, while the torque is the inverse of the momentary drive speed. And that's true for any power. The only thing we do by changing the braking resistance is scaling the de-acceleration curve.

For another drive, you had to look at the M/n characteristic first, then deduce the power to speed relation from that. But this curve is very common for vehicles because it's so favourable.

Your understanding of power is incorrect. Energy is stored inside a moving mass, not power. Power is energy divided by time. So, you can de-accelerate either quickly (high power) or slowly (low power).

Let's take a simple example: a 1920ies streetcar. One of the most simple arrangements driving electrical. It has a series DC motor and some resistors on the roof top for braking.

Let's say we have an energy of 50kWs stored in the moving mass of the car. The resistive breaks can take up to 10kW without overheating. So, using the electrical brake at full power, we should be able to bring the car to standstill in five seconds. Okay, but: can we employ that?

Mechanical power is torque times drive speed

$$P \sim M \cdot n$$

but what is the torque/speed relation? Luckily, the drive of such a 1920ies streetcar has a torque/speed characteristic which is roughly a hyperbolic curve.

$$M \sim \frac{1}{n}$$

Torque is very high at low speeds and low at higher speeds. This is very practical for both accelerating and braking. So, the power we can break at is

$$P \sim \frac{1}{n} \cdot n = 1$$

So, yes: we can brake the streetcar with constant power, while the torque is the inverse of the momentary drive speed. And that's true for any power. The only thing we do by changing the braking resistance is scaling the de-acceleration curve.

For another drive, you had to look at the M/n characteristic first, then deduce the power to speed relation from that. But this curve is very common for vehicles because it's so favourable, making it possible to make full use of the power rating of the equipment at all speeds.